The derailleurs stops can come out of adjustment and when they do it can cause skipping. The pulleys will not be aligned with the cogs and the chain will be "teetering" on the cogs. When power is applied it can skip. It's best to check them whenever doing drivetrain work.
Originally Posted by
Homebrew01
The stops adjust how far the derailleur can move at the extreme ends ... biggest and smallest cog. The stops will have no effect on fixing skipping due to chain and or cassette wear. Since only the chain was changed, there will be nothing to adjust, because the derailleur and cassette are still in the same position. After changing the cassette, there is a possibility the derailluer will need a tiny adjustment, if the new cassette sits at a slightly different spot on the freehub. In that case, cable tension will also need a slight adjustment to realign the derailleur with the cogs.