You might encounter an error while opting to delete messages on Facebook messenger due to tech glitches. However, to get rid of them, you can always use the assistance of the help team to get the issue resolved or you can connect with a help center that has a host of FAQs to remove the errors that you might be facing using the diagnostics.
I’ve experienced this kind of problem before but I think its just a short glitch. Just try to restart or refresh the app and it would work now. If it still doesn’t then maybe try after a couple of minutes. Then while waiting for your messenger problem, why not try and play Pixel Gun 3D game on your PC. With EMULATOR app, you can easily play this mobile game on your PC. Download the app now and go to this game while killing some time. Have fun!