Just a note that may save you some time if you're using both Studio configurations and DAM…

I found that after deploying the Studio jar file on the server that assets of Doctype 'File' were no longer included in the list of DAM assets.

DAM expects an asset to have the facet 'Asset' assigned to it, and doctype 'File' normally will unless you deploy a Studio jar with default settings.

Within Studio, under Content Model -> Documents -> File under facets you'll need to manually assign the 'Asset' facet to 'File' and any other doctypes that you want to use with DAM.

DAM contributions in the file dam-core-types-contrib.xml try to append the 'Asset' facet to 'File', but the Studio file definition later overwrites it with the settings from Studio which doesn't have 'Asset' set by default.

Don't know if it is possible, but if Studio can know that the target system has DAM deployed, the 'Asset' facet should be automatically assigned to non-folder doctypes.