If you go to https://drive.google.com, verify you are logged into the account you would like to share files from. If not, switch to the account that has the Google Drive file.

Afterwards, refresh the Eduflow submission activity page and try again.

Browsers are getting more strict when data is exchanged across websites, meaning you may need to ensure you've permitted both Eduflow and Google Drive to talk to each other.

Check your browser settings to see if you are blocking cross-site tracking, third party cookies, or haven't authorized app.eduflow.com - or whichever domain Eduflow is hosted on - to your cookie whitelist.

If you've encountered the error "The feature you requested is currently unavailable. Please try again later.", this may apply to you.

To allow cookies, you can try this guide: https://help.eduflow.com/en/articles/4598908-how-to-allow-cookies

Afterwards, refresh the submission activity page before trying again.

Some browser extensions, notably ad blockers like AdBlock and uBlock, are known to block Google Drive.

If you try disabling browser extensions you have running in the browser, you can refresh the submission activity page, and try again. If it works then, the extension may be the cause.

Sometimes files aren't allowed to be shared due to file settings. To check if a Google Drive file has had sharing restricted, open "Sharing" for the file an click the cog:

If "Viewers and commenters can see the option to download, print, and copy" is unchecked, assure it's checked:

Afterwards, refresh the submission activity page and try to attach the file again.

When trying any of the solutions on this page, always refresh the submission activity page after.

Contact support and let them know the Activity URL you are having an issue with and what you've tried so far.