Missing submissions error - OJS 3.0

Hi there,
We’ve just migrated over to OJS 3.0, mid-production and in doing so somehow managed to generate an error in the dashboard when signing in to view recent submissions. When a journal manager or editor signs in, the following dialogue box appears:
When you click through the OK prompts it eventually follows through to the submission screen where there are zero submissions listed - we do know that we have submissions and these were originally accessible through the dashboard - any clues on what this error could possibly mean and how to resolve it?

Thanks for your help! :slightly_smiling_face: