If your TestFlight public link returns a "This beta isn't accepting any new testers right now." error you can try a couple of solutions to resolve the issue:
1. Check the Build status
Go to App Store Connect
Select the app that you want to run the playtest for
Click on TestFlight
The Builds page will open by default. Check the status of the build that you want to playtest with. You should ideally see a green check mark and the Testing status.
Other build statuses and how to resolve them:
Expired: TestFlight allows builds to be tested for a maximum of 90 days. If you see this status, you need to submit a new build to TestFlight before you will be able to run a playtest.
Approved with a yellow dot next to it: This indicates that your app has been approved for testing but is still being processed. You need to wait for the processing to complete before you can run the playtest.
If you see a Notify Testers link next to the Approved status, click it and check the status in a few minutes to see if the green Testing status has appeared
Any other yellow status: This indicates that your app has not cleared the review process yet and is not ready for playtesting. You need to wait till the review process completes or check with Apple on the status of your build
2. Check the External Testing group settings
Go to App Store Connect
Select the app that you want to run the playtest for
Click on TestFlight
Click on the name of the external testing group you created for your playtest
Things to check on this page:
The public link is enabled: If you see Enable Link next to the public link, click on it to enable the public link
Set a high Tester Count: The error could be caused by the tester count limit being exhausted. Click on Edit limit and set a high number to resolve the error.
Check the build associated with the group: Under Build you can see which build is available to players through the public link. Check to see if the correct build is listed and the status is Testing. If you see any other status next to the build, refer to the Check the Build status section of this article to resolve the issue.
Following these steps should resolve the error in most cases. If you are still seeing the error, please reach out to us at hello@playtestcloud.com.