Gravity Falls, despite being instantly heralded as a classic and one of the defining series of the Disney Channel, suffered constant issues due to its creator Alex Hirsch's lack of experience in running an entire show (he was only 27 years old when it started). By the time the first season wrapped, Hirsch was so exhausted that he seriously considered ending the show right there, leaving it forever on an incredibly tantalizing Cliffhanger. It wasn't until he shared his plans with Jon Stewart, a huge fan who was horrified at the idea, that he decided to press on, though cutting his plans for the show to run three seasons down to just two. The Disney Channel execs weren't very happy about losing one of their most acclaimed shows so soon and forbade him from revealing the plan to end the show to the public until the season was almost over, spending the entire time in between trying to talk him into continuing it to no avail. When the announcement finally couldn't be put off anymore, Hirsch was a complete stand up guy about it, making clear that the two season run was entirely his own decision and the fans shouldn't blame anyone at Disney for it, and ultimately came out of the experience with a highly acclaimed project he got to end on his own terms, about the happiest ending to the story possible.
Iron Man was also a mess behind the scenes, with Marvel viewing it as an afterthought whose sole purpose was to sell toys. The second season had no producer until three months into production, which resulted in 2-hour work days with no weekends off. The staff also had little say in things about plots and character designs, which were largely dictated by Marvel and Toy Biz.
Many of the season 1 episodes were massacred by bad outsourcing, due in part to work from the cheapskate, sweatshop conditions of Fil-Cartoons, who handled ink-and-paint work for the entire first season, and more often than not heavily ruined many scenes due to their all-around cheap Xeroxing, ugly colors and even "reworking" drawings or whole scenes of animation; there were even some unintentional (rather than purposeful) off-model moments, such as Stimpy's eyes inexplicably turning black in the "Stimpy's Breakfast Tips". Carbunkle director Bob Jacques had to fight tooth and claw to get the studio to turn in acceptable work for episodes like "Stimpy's Invention" (and even then the sporadic error slipped in, such as Stimpy's eyes floating off his face when he's showing Ren his new socks), and described the experience of working with them as "all damage control".
One of the biggest sources of friction was over censorship. Nickelodeon was always uneasy with the gross-out nature of the show's humor, and shelved one episode, "Man's Best Friend", due to its violent and scatological content. As a general rule, anything that had to do with religion, politics, alcohol, and tobacco was put under a microscope by Standards & Practices; the character George Liquor had his last name removed from one episode and made only sporadic appearances due to opposition from the network, right down to axing an entire scene with him from "Rubber Nipple Salesman" and forcing Spumco to change a Liquor cameo in "Haunted House" into a parody of Doug Funnie (a scene that got edited out in reruns anyway), while "Powdered Toast Man", featuring The Pope, removed a cross from his hat and credited the character simply as "The Man with the Pointy Hat", and the ending scene of Toast Man carelessly using the Constitution and Bill of Rights as kindling for a fire got edited out after its initial airing, which ironically ruined the episode's satirical message of how easily authority and power are abused.
The show suffered from severe Schedule Slip almost from the start, the result of, depending on who you ask, John Kricfalusi's perfectionism or the constant battles over what was acceptable to air. Nickelodeon had to rerun the pilot episode in order to have something to show in what would've been the second episode's time slot; this helped the show build an audience but killed any hope for syndication. This became a trend; the first season had only six episodes air between August 1991 and February '92.
Feuding between John K. and Nickelodeon over Schedule Slip and censorship came to a head in September '92, in the middle of the second season, when Nickelodeon fired John K. and took over production themselves via the in-house studio Games Animation. The exact circumstances of John K.'s firing are hotly debated to this day; John K. cites his refusal to censor "Man's Best Friend" as the final straw for Nick, while others blame the Schedule Slip. Regardless, this is the moment when many fans claim that the show took a notable downturn in quality, especially given that a good chunk of the staff left in protest at John K.'s firing. Ren & Stimpy finished its second season and ran for a total of three more before it was canceled at the end of 1995 (though one last episode aired on MTV the following year).
Later on, in 2003, John K. relaunched the show as Ren & Stimpy "Adult Party Cartoon", part of an adult animation block on Spike TV. The show once more suffered from Schedule Slip, though the censorship fights at Nickelodeon were inverted at Spike TV; John K. maintains that Spike TV pressured him to turn up the adult content farther than he was willing to go. In any case, the show only lasted two months and seven episodes (the pilot being the previously-unaired "Man's Best Friend") before being canceled.
Years later, John K. was accused of having sexually harassed several young interns during the Adult Swim run, threatening to destroy their careers if they didn't let him have his way, which contributed a lot to the hostile work environment and the show's short run.
By 1979, The Scooby-Doo Show was on the verge of cancelation by ABC, and Joe Barbera came up with the new character to help save it. None of the on-staff writers at Hanna-Barbera could write a satisfactory pilot script, and Evanier, the editor of their comic book division, was chosen. Barbera and Evanier worked together to finalize the character, and Evanier eventually turned in a satisfactory pilot script, and the show was picked up for a full season and made it on the air following endless salary and billing disputes, conflicts with Standards & Practices, and much muchExecutive Meddling.
Casting the character's voice was difficult in its own right, and the entire pilot was recorded at least five different times. Mel Blanc was Barbara's first choice to voice Scrappy, but he turned the role down over salary disagreements. Then Frank Welker was considered before Don Messick was cast, and the pilot script recorded with the entire cast. Then ABC decided they didn't like Don's version, so Daws Butler was cast and the entire script re-recorded. Then they didn't like his version, and Marilyn Schreffler was cast and the script re-recorded once again before Welker was cast, and the entire script recorded a fourth time. Then Paul Winchell and Dick Beals were cast at different points, though production was halted while Barbera once again attempted to strike a deal with Mel Blanc. Ultimately, Lennie Weinrib was cast in the role simply because he was the first choice the network wouldn't veto. Even he would end up leaving the role at the end of the season over a salary dispute, along with a personality dispute with the voice director, and Don Messick became Scrappy's permanent voice afterward.
The original designs were chosen by the executives were apparently butt-ugly* (and considering that art-style the final series has is still significantly divisive, that's saying a lot), and the crew had to fight tooth-and-nail to get designs that were more appealing.
The executives seemingly didn't know what kind of show they wanted to see: a subversive self-parody of the Scooby-Doo franchise with the character's personalities exaggerated or something more traditional for the series. They ended up forcing the first several episodes to be rewritten from scratch over even the slightest of issues they had with the characters, delaying the show's premiere date and wasting several hundred thousand dollars in the process. The execs then blamed their losses on the writers.
The execs arbitrarily replaced the show creator and the main writer with an inexperienced writer in the middle of the second season and gave the former two no credit for what they actually did during the said season. The show creator eventually gave up and left the show due to how nasty things were getting behind the scenes and how the execs were treating him.
The pilot episode of The Simpsons, "Some Enchanted Evening" went so badly wrong that it nearly killed the show before it even began. The big problem was that the key members of the production team didn't appear to be talking to each other. Matt Groening and James L. Brooks imagined a show with unique designs and color schemes, but characters who were animated in a realistic way. Animation director Kent Butterworth (and apparently the people at Klasky-Csupo) on the other hand thought it should be animated in a whacked-out, over the top style with little regard paid to keep the characters on model. And nobody appeared to have told the Korean animators anything at all, meaning they were let loose on the episode with wildly inconsistent results. The end product, while sometimes defended by animation enthusiasts as for how the show should have been animated, wasn't what the producers or Fox wanted at all, and the plug nearly got pulled on the series. Fortunately the second episode, "Bart the Genius" did fit what the producers were looking for, and so they reshuffled the episode order and kicked off the series with "Simpsons Roasting on an Open Fire," while "Some Enchanted Evening" got substantially re-animated and booted to the end of the season.
There is a notorious story surrounding the first time the staff saw "Some Enchanted Evening". In one scene, Bart and Lisa watch a Happy Little Elves cartoon. For some reason yet to be determined, Butterworth had decided to have a bear tear off one of the elves' heads and drink its blood. Needless to say, this did not go over well with the production crew.
One major problem during production was that they couldn't make up their mind what kind of cartoon this was supposed to be—studio head Phil Roman was most comfortable with the plot-and-dialogue-driven approach used in his commercial successes Garfield and Friends and The Simpsons, and had given this series what seemed like a guarded blessing—there was one group who wanted a Felix like the Otto Messmer shorts, one group who wanted Max Fleischer surreality, Don Oriolo, the current owner of Felix, wanting it to be like his dad's made-for-TV Felix cartoons (which most of the staff working on the show were against—they ultimately, but begrudgingly, added certain elements from it into Twisted Tales, like the Magic Bag), one group who wanted the show to be Ren and Stimpy-esque (understandable, since some of the artists on the show were former Ren and Stimpy artists), and one director who wanted a Robert Crumb influence! With so many cooks in the kitchen, the direction of the show tended to be all over the place, with Felix himself often getting swamped in importance by a large cast of supporting characters and his chaotic world. On top of that, per word of Mark Evanier, the studio had a terrible time finding a voice for Felix, saying they may have set a new industry record for most actors auditioned for one role (to where even staff of the studio were trying to audition for the role), and they wound up recording the show with a "scratch" (temporary) voice and animating to that. The final voice was only selected a few weeks before an episode aired and was dubbed in.
Another problem was that in addition to having a month to storyboard, design and do layout work on each short, they could not learn from their mistakes, because by the time film began to come in, the season had been just about wrapped up. Some directors could handle writing and boarding a good cartoon, while some couldn't. The artists had no say on retakes in animation either, which was left to Phil Roman to decide—and unfortunately, the overseas animation on the show tended to be rather sluggish. This only got worse with the second season, with Korean company Plus One having to rush episodes through, resulting in sloppy artwork and very bad animation timing (with "Nightmare on Oak Street" being one of the worst examples in the second season). On top of that, they were behind schedule, so they couldn't order retakes to correct any mistakes.
Eventually, Phil Roman and Don Oriolo found the "Cartoonist Driven" approach of the first season to be too taxing on them, and not even worth the trouble since, despite being one of the most expensive shows that Phil Roman's studio had made, the first season turned out to be a flop in ratings, due in part to a terrible time slot—it was sandwiched right between sports shows and then-ratings giant X-Men, making it very hard to establish an audience for the show. On top of that, Don was just unhappy with the weird direction of season 1 having almost nothing in common with Joe Oriolo's Felix, so the second season went through an extensive retool—while the first season was storyboarded while working from a basic outline, and was absurdly surreal in its premises and animation, the second season decided to take the series into a direction more in vogue with the Joe Oriolo Felix cartoons and shift production to make the show a more standard TV cartoon, with scripts replacing the all-storyboard approach (usually provided by the writer of Garfield and Friends, Mark Evanier, who has remained silent on the series ever since), resulting in much more linear plotting and less surreal humor and more emphasis on wordplay and one liners, as well as bringing back some of the Oriolo era characters like Poindexter, Master Cylinder and The Professor while forcing most of the new side characters to be scrapped in turn. This move was met with outright hostile reception from the shows staff, particularly the producer of the first season, who knew Don's meddling would only make things worse and bailed on the show just two weeks into the second seasons production. They even tried to have the writers voice direct the actors instead of the directors, but after a couple weeks of trying that, the results were so disastrous that the studio was forced to drop that and hand over voice direction back to the cartoon directors. The staff retaliated by writing whole episodes that took jabs at the second seasons toned down retool, such as "Attack of the Robot Rat" (which infuriated Don Oriolo for being a ruthless parody of his dads made for TV Felix the Cat cartoons), "Phoney Felix" and "The Fuzzy Bunny Show". The first few scripts they received were followed closely, but the shows new producer finally fought for the artists to have more storytelling and creative control on the show, and they were able to completely scrap the scripts and write their own shows, ironically giving the crew more freedom than they had in the first season. Some episodes were tightly scripted and some were not. Unfortunately for them, the VP of Children's Programming, Judy Price, who wanted the show picked up in the first place, got fired, and Felix the Cat Inc. was so unhappy with the show in general that they refused to renew the license for Phil Roman to continue using Felix, guaranteeing a third season wouldn't happen. To make matters worse, the second season turned to be an evenbiggerflop in the ratings, and it ultimately got the show canned, with season 2 ending after just 8 episodes. The second season was considered a disaster in the eyes of everyone involved in it (especially Don Oriolo, who is barely willing to acknowledge the existence of Twisted Tales these days) and the show's failure ultimately put the Felix the Cat cartoons on ice yet again (having already gone through it with the 1991 movie, which was a box office bomb), with only low key revivals coming of the series after the fact.