Meddler:
"To give you some context on Caitlyn we originally disabled her due to a bug with her ult, where it would grant permanent vision against targets with spellshields. We got a fix for that in, but the fix for that ended up introducing a different, more serious issue that could cause games to crash. We disabled Caitlyn again as a result, and are working on a fix for that second problem.
As a side note this sort of occurrence is the reason we don't hotfix more than we do. Hotfixes are a great tool for addressing something quickly, but they don't have a full patch development cycle's worth of time to get tested however. As a result there's the risk of introducing something as serious, or more serious, as the problem you're trying to address. Because of that there's a certain threshold of problem needed before we feel a hotfix is worth the risk. Some bugs that we've got a fix for therefore get addressed in the next scheduled patch, rather than in an immediate hotfix."
"We're working on a fix still, leaving a champion disabled for a significant period of time is something we do our best to avoid, so if it's practical to we hotfix for disables. The exception to that is we know the fix has a high risk of breaking other things we avoid hotfixing and put the fix through a full testing cycle (e.g. if modifying code that affects a number of other game elements too, which is what lead to Viktor/Rumble being disabled for an extended period)."