ClinicOffice freezes whenever I try to delete an apt

We are using COv4. Whenever I right click an appointment and select delete clinic office freezes. The only way I can get out of the situation is to close Clinic office on the task manager. This is a new problem as of this week. Last week we didn’t have any patient info in the short cut tab, and that has been rectified but it seems in doing so we have created another issue. Can you offer any advice?