If you were working off of main branch/github (and not the 4.7 release), there were a few weeks where component bound blueprint events were getting corrupted. I fixed this bug in change #2519532 (https://github.com/EpicGames/UnrealEngine/commit/210f5edba9590a79c2c3bba6ec9985efb85c99c9), and that change includes some hacky code to try and fix up the broken events. I reverted the hacky fixup code in change #2519536 (https://github.com/EpicGames/UnrealEngine/commit/5f90c74af8ccc9dd25c96989624844429c8be1f2) because it’s not 100% safe in the general case, and this issue only affected people on the main branch.
So, can you try re-adding the code I deleted in #2519536? That may fix up your broken nodes for you.