Hello karl-godwin,
For every bank errors, there are different reasons why this occurs and how we can fix it. May I know what is the error message or code you received?
Meanwhile, we can do a few troubleshooting steps to get this working. You can use a private browser because it doesn't store cache. Aside from the regular browser you're using, you can also use other supported browsers as alternatives.
From there, you can attempt to connect Clydesdale bank to QuickBooks Self-Employed again.
Keep us posted of the results so we can further assist. Additional details would be much appreciated.
