I have saved Sketchup files .skp, created on my iMac desktop, to Google Drive and can access these from the Google Drive fine from my desktop.
However, my Macbook Pro which is logged into the same single license version of Sketchup Pro 2019, is not able to save files to the same Google Drive or open files from the Google Drive location?
On attempting to open a file from the Google Drive the error message is ‘File not found or invalid’ then 'The Document “XX.skp” could not be opened.
On trying to Save a file to the Google Drive the message is - ’ The document “XX” could not be saved as “XX”.
Are you trying to open the .skp files directly from Google drive and then trying to save directly to Google drive? If so, that’s a risky move. We’ve seen numerous cases in which users doing the same sort of thing wound up with corrupted and unrecoverable SketchUp files.
Can you download the file from your Google drive to the Documents folder on your MacBook Pro and then open them?
When you save your work you should save to the local drive in your computer and then sync the file your Google Drive account.
That may be a connection speed thing. Even on the Desktop, you should download to the local drive, work on the file, save it locally, and the sync to the Google Drive. This practice will reduce the chance of corrupted files and also leave you with a back up version.
As above, I would save the file on the local drive, upload a copy to the cloud and download that to the other computer when you want to work on it. You could use Trimble Connect as your cloud storage, too. Even so, work and save locally.