I have caused the error myself! I made it too easy for myself and used the PopTray.ini from version 5.0.15 for version 5.3.0 to save me having to create the accounts again. The PopTray.ini from version 5.0.15 is too old and not compatible with version 5.3.0. I reinstalled version 5.3.0, re-created the accounts and it works fine.
I'm using PoptrayU 5.0.15 with t-online and Yahoo mail on Windows 10 so far. For Yahoo mail I had to create an app password at Yahoo for it to work. I have now updated PoptrayU to 5.3.0. The interval check only works once. When I check again, I get an error message for all accounts and have to kill the task for PoptrayU. I only have the PopTray.ini and Rules.ini from PoptrayU 5.0.15 transferred to version 5.3.0 -- Regards VanFlusen mailto:VanFlusen@yahoo.com