Smartsheet Merge with Google Docs error

Hello. I use the Google Docs merge integration with Smartsheet, but within the last 2 weeks I continually receive an error when attempting to merge. The error reads: ScriptError: Service unavailable: Documents. The error appears when I attempt to "Select a sheet". I have attempted uninstalling and reinstalling the integration, but the error persists. We do not use GSuite.

Any ideas how I can resolve this error? Screen shot for reference.