Change SQL Server user SID

I had a similar situation with a deleted AD user and SID mismatch. For me, the problem was local SID caching and the solution was to follow the workaround in the link below on the SQL server and client's pc.

  1. Open Registry Editor. To do this in Windows XP or in Windows Server 2003, click Start, click Run, >type regedit, and then click OK.

    To do this in Windows Vista and newer, Click Start, type regedit in the >Start Search box, and then press ENTER.

  2. Locate and then right-click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa>

  3. Point to New, and then click DWORD Value.

  4. Type LsaLookupCacheMaxSize, and then press ENTER.

  5. Right-click LsaLookupCacheMaxSize, and then click Modify.

  6. In the Value data box, type 0, and then click OK.

  7. Exit Registry Editor.

Optionally, afterwards, right-click the LsaLookupCacheMaxSize DWORD you created and delete it.