Based on my research, this issue may occur due to corrupt Outlook data file. Since you are using Exchange account, to verify this, we can try switching to non-cache Exchange mode to check if this issue continues. If the problem would be gone in online Exchange mode, please try deleting the old .OST file and then restart Outlook to sync a new one to fix the issue. Basically, the OST file is by default saved in the following folder:Based on my research, this issue may occu