If you're trying to send a file to anyone with the link (no email verification) with "Expire after opening", you'll see this warning.
"Expire after opening" will apply once the file is viewed by the first recipient
When Access is set to "Anyone with the Link (No email verification)", anyone with the link will be able to access your file.
None of the recipients who access your file will be required to verify their email address. Therefore, our system will not be able to differentiate between each unique recipient, and correspondingly, assign a countdown timer to each recipient.
As such, the countdown timer will start the first time the file is viewed. When the file expires, it will no longer be accessible to anyone.
How to enable "Expire after opening" for multiple recipients
Option 1: Require each recipient to verify their email address
If you want a file to expire after opening separately for each recipient, you must require each recipient to verify their email address when accessing the file.
To do this, select one of the following under Access:
Only people I specify
Only people from domains I specify
Anyone with the link (email verification)
Option 2: Send multiple links
Alternatively, you can send separate, one-time links to each recipient with "Expire after opening" enabled. Each file link will then have its own countdown timer.