Maybe it is related to the Premium Package add-on. Try deactivating Premium Package add-on if you have it. We are releasing an update of that add-on soon to fix the issue.
If it is not related to Premium Package and having this issue in the frontend, then that might be a Bootstrap conflict. You can disable WPDM Bootstrap from Downloads Settings Misc panel.
Please send temporary wp-admin login info in private reply if none if the above suggestions work.