This error can occur when the Airtable base structure becomes out-of-sync with miniExtensions. Normally, any changes to fields, tables etc. in Airtable sync across to miniExtensions automatically, but in some rare cases this automatic sync can fail.
If you come across this error, please try refreshing your base manually by going to:
Your extension's configuration page
Clicking on the Options menu towards the top of the page
Selecting Refresh base
This should bring the base structure back in sync and resolve the issue. If you refresh your extension, the error should be gone. If it doesn't disappear, please ensure that you haven't deleted any tables from Airtbale that are used by the extension. You can always restore them from Airtable's trash if that's the case and then remove them from miniExtensions first before deleting them again.
If none of this resolves the issue for you, please contact support with details about when and where the error occurs exactly, so we can help you troubleshoot.