Darkness and Light: Part 1 - S1-E11
Plot hole: When Hulk and Banner have been physically separated by the nutrient bath, they are both wearing tattered pants. Given that Hulk and Banner were previously occupying the same body, this should not be possible. Hulk was the one that went into the nutrient bath, so if Banner's body was separated from Hulk, then Banner should be naked.
Suggested correction: It was done deliberately as a form of censorship. They didn't want to show Bruce's genitals.
Explaining why the mistake occurred doesn't invalidate it. Unless you're suggesting the nutrient bath also was able to duplicate the pants.
You realise a character can be drawn naked without actually showing their genitals (and/or breasts in the case of women), right? The Little Mermaid is a good example of this.
Continuity mistake: When Jennifer Walters is first introduced, her fingernails are unpolished. Later when she is restrained in Dr. Doom's lair, her fingernails alternate between being painted pink and red. Given that she and Bruce were running for their lives, she wouldn't have had time to paint her nails. Later when she transforms into She-Hulk, her fingernails turn green with the rest of her body, but if her fingernails were painted, they should still appear that color, as her skin and hair turning green wouldn't magically remove nail polish.
Helping Hands, Iron Fist - S1-E4
Factual error: When Bruce Banner sees the Hollywood sign reflected in the puddle of water, the reflection is backwards.
Audio problem: When Talbot comes upon the Hulk in his helicopter, the helicopter doesn't make a sound until it appears on screen.
The Return of the Beast: Part 1 - S1-E1
Factual error: When the Hulk jumps up and grabs on to the tail of the helicopter, he is somehow able to hang on to the tail while spinning the helicopter in a circle. Helicopters require a certain weight distribution in order to maintain stabilized flight. Someone of the Hulk's size and strength wouldn't be able to just hang on to the tail and spin the helicopter. He instead would bring the helicopter crashing down.
The Return of the Beast: Part 1 - S1-E1
Continuity mistake: When Banner is strapped to the chair and trying to resist transforming into the Hulk, the extent to how much he has transformed varies. Some shots will show his hands and head becoming larger, and the next shot will show him to instantly be back to normal proportions.
Plot hole: After Dr. Doom's robots abduct Jennifer and load her into the aircraft, Hulk hitches a ride all the way to Doom's estate, falling off the aircraft and breaking into the estate before the aircraft has time to land. Despite this, Dr. Doom already has Jennifer secured to an infirmary table and medical machinery by the time Hulk confronts Doom.
Man to Man, Beast to Beast - S1-E6
Plot hole: This series is in the same continuity as the other Marvel animated series that aired around the same time - X-Men, Spider-Man, Iron Man and Fantastic Four - by virtue of each aforementioned show crossing over with at least one of the other shows. However, the portrayal of Sasquatch between this show and X-Men is not consistent. In X-Men, Sasquatch was a mutant and longtime member of Alpha Flight, under the purview of the Canadian government. In this show, Walter Langkowski is a hermit that had only recently become Sasquatch through a gamma experiment gone wrong, and he chooses to exile himself into solitude by episode's end.
Man to Man, Beast to Beast - S1-E6
Other mistake: When Gabriel Jones talks with General Ross, his fingernails are perfectly visible, even though he is wearing gloves.
Darkness and Light: Part 3 - S1-E13
Continuity mistake: When Doc Samson tackles the new Rick Jones-Hulk hybrid and knocks over the cylinder for the nutrient bath, Banner spills out, and you can see he is wearing shoes. A few moments later when Banner begins to run outside, he is suddenly barefoot. (00:19:44 - 00:20:10)
Darkness and Light: Part 3 - S1-E13
Continuity mistake: When Ross is getting ready to sabotage the experiment, the equipment on the wall next to the fire extinguisher changes appearance. A white label also appears on the front of the extinguisher. (00:19:07)
Darkness and Light: Part 3 - S1-E13
Continuity mistake: When Ross is threatening Banner with a gun, there is a shot that shows Banner frozen in place and the camera zooms out to show that the shot was reflected from the pupil of Ross' eye. Since it was a reflection, the flower on Banner's robe should have been on the viewer's left since the actual Banner has the flower on the viewer's right. (00:13:32)
Darkness and Light: Part 3 - S1-E13
Continuity mistake: When Banner re-engages Hulk in the desert after Hulk disposes of Talbot, the face guard for the exoskeleton armor Banner is using is missing, but then reappears when Banner launches the armor's right foot at the Hulk's backside. (00:07:38)
Darkness and Light: Part 2 - S1-E12
Audio problem: When Betty tells Bruce that Hulk is on a rampage, Bruce says "It just never ends," but Betty's mouth is the one saying the line.
Darkness and Light: Part 1 - S1-E11
Continuity mistake: When Doc Samson first breaks through the floor of the vehicle that is transporting the Hulk, his arm is emerging next to the platform that Hulk is secured to. When the shot changes, Samson's entire body is coming through the hole, and the base of the platform is nowhere to be seen. (00:19:54)
Darkness and Light: Part 1 - S1-E11
Continuity mistake: When Doc Samson kicks through the cab wall of the vehicle that is transporting the Hulk, he leaves a hole roughly the size of his leg, and the appearance of the damage suggests he kicked through metal. A couple of shots later, the hole is large enough for a person to fit through, and the appearance of the damage suggests it is now broken glass. (00:19:56)
Darkness and Light: Part 1 - S1-E11
Other mistake: When Doc Samson attacks the convoy, he begins by bursting his hands out of the asphalt. This is pretty illogical, as for him to be able to wait for the convoy to reach him and then break his hands through the asphalt at the right moment would mean he would have to be inside the road itself, which means there would have to be a void between the layer of asphalt and the surface beneath it large enough for a person to fit inside, which would be a hazard, as the weight of cars passing over would eventually cause this section of the street to collapse.
Darkness and Light: Part 1 - S1-E11
Continuity mistake: When the S.H.I.E.L.D convoy is taking Hulk away, they are shown driving down a desert road, with large rocks on the shoulder. When the shot changes, the road is suddenly adorned with street lights. (00:19:43)
Darkness and Light: Part 1 - S1-E11
Continuity mistake: When Rick Jones comes to tell Betty that S.H.I.E.L.D. has taken the Hulk, he is standing by the door, and she is standing at the foot of Banner's bed. When the shot changes, they are both suddenly standing in front of a large window. (00:19:05)
Darkness and Light: Part 1 - S1-E11
Continuity mistake: When Doc Samson is using the defibrillators on Banner, Banner's pants are suddenly adorned with a belt, which has disappeared when Betty starts cradling Banner's head. (00:15:20)