Can anyone suggest how I find out the 'An unexpected error has occurred' I'm getting when deploying?

does it tell you the object type/id at all? if not, if it is a dev/sandbox target account I just used process of elimination in the deploy.xml file to determine what the problematic object was

I have encountered errors of that kind when using a version of SDF not intended for the account. Has the target account been upgraded to 2019.2 recently?