This issue is commonly caused by the FinOps users being disabled.
To check this:
Login to FinOps Administrator
Browse to System Control, Users
Ensure that the affected user has a tick in the Enabled column
If they do not, click Edit (hand with a question mark icon) and tick the user as required
Click Save (green tick icon) to save the changes
If this doesn't resolve the issue, our support team will need to investigate, run scripts or liaise with the hosting or development teams. Any Issues with contacting us, please see the following Get support in Financial Operations.