Last week a Hotfix was released to remove deleted custom fields because the new reporting can only show up to 40 custom fields.
Today I found that existing legacy reports that utilized custom fields are now showing custom fields not previously selected.
I suspect that by clearing the deleted custom fields the custom field in the legacy reports will also shift up and you will end up with reports that have custom fields in them that are wrong.
So if you use custom fields in you reporting you will need to fix them.
I have also had one occurrence where one of my View Filters that uses custom fields broke after I edited and saved it, some of the fields had a "undefined" value instead of an "*".
I hope this hotfix is not going to break any of my agent procedures