So, I am at the part in chemical crisis where you come to the forklift. Now - Somehow batman went up the pipes to open the hatch, and then I switched to Robin. Next thing I know batman is in the fenced off portion beneath the glowing panel and I can't get out.
As Robin (in Hazzard Suit) go to the left side of the area (need to lower the ladder with batterang first). Use the switch near the lid, and hop in the water. Go right into the circular area & swim up (hold jump button). Use the switch above the last chemical vat & it lowers the water. The fence surrounding the vat moves out of the way, and you can use the vat to get the last chemical. This should automatically take you to the next area. Thus Batman would be free, though I think you can get a mini-kit or something cool where he got "stuck".
Hopefully that works, if not pause & exit the map. You will have to start over, but it beats getting stuck.
I ran into a bug in this level where you fill the 3 different vats with Robin, and it's supposed to turn the two orange geysers into water. The cutscene never played, making it impossible to proceed. Thankfully it was right after a checkpoint, because I had already played that level for 2 hours before it got the bug.
I nearly raged when I started over and I was back in the Batcave. Fortunately when I got back to the level, it started me off at the checkpoint.
i had a problem on that level as well. Took me forever to figure out I needed to freeze the 2 geysers to get to the next platform. and at the end Robin and superman got on the elevator but i was busy picking up studs took me another forever moment to glitch myself up there.