[500] Internal Server Error: Cannot execute as the database principle because the principle "dbo" does not exist, this type of principal cannot be impersonated, or you do not have permission (4222481)

When navigating the Website, the following error is displayed:

"[500] Internal Server Error: Cannot execute as the database principle because the principle "dbo" does not exist, this type of principal cannot be impersonated, or you do not have permission"

You may also notice that no new information is being written to the database. The Journal Mailbox and ESM Mailbox scanning may not be working.  

1. Open SQL Server Management Studio

2. Right-click the ArchiveManager database | Properties

3. Click Files

4. For "Owner:" it may be blank

5. Add the SA account, or an account with sysadmin rights as the Owner

6. Click OK to apply 

7. Refresh your Archive Manager website and the error should no longer be present.