Searching external resources returns "An error has occurred, please try again later and contact the system administrator."

The search in an external source used to work but suddenly we got an error message. Why does this happen?

Please check the following:

- if the resource requires credentials: verify that your credentials are still valid and correct

The credentials are correct, but you still get the error:

- use an incognito window and perform the search there

The search is working in incognito:

- clear your browser cache and cookies (long term, ie last 4 weeks, not just 24hrs)

The search is still not working:

- open a support case