Operating system: Windows 10
Graphics card: GTX 760
Broken: 2.80, Hash: d30f72df8ac, 2019-06-19
If you filter the action editor by errors it will not show any unless you have seen them. This makes it very tedious to find errors with my keyframes. I've added a gif to show the problem better.
Exact steps for others to reproduce the error
Make an armature with several bones and create an action with keyframes for all of the bones.
Delete one of the bones.
If you don't have enough space to show all the channels in the action editor then the filter by error thing will not correctly show you the keyframes for the missing bone.
If you scroll down and see the errors with your own eyes, the filter will work.