Hello,
I have removed some custom fields which we don't use anymore.
After I have deleted them, we are getting the following message when opening a project:

When I view the error, I see the following message:

This is indeed a field which I have removed and may be in use by something.
But how can I check this / get rid of this error?
I can't find this field anywhere since we deleted it.
Thanks in advance!
Mitch