Whenever you 're experiencing problems with DigiCal, it usually helps to restart your phone or reinstall DigiCal. It should solves most of the problems.
0. Update to the latest version of DigiCal through Google Play Store;
1. Re-install DigiCal and DigiCal+. Please make sure to double check that you make use of the account that you purchased DigiCal+ with;
2. Restart your Android device.