I recently disabled the default admin account on my Synology NAS device as part of an exercise to make it a bit more secure. However, after doing so I found I was unable to access any of my shared folders.  The message I was receiving was:

“This user can’t sign in because this account is currently disabled”

My first thoughts that is was something on the NAS but as it turns out it is Windows Credential manager which is attempting to connect using the account I disabled.

Fortunately, the solution is nice and easy, just go into Control Panel –> User Accounts –> Credential Manager –> Windows Credentials and delete the existing entry and you should be able to connect now.