This might be because of some pending temporary decrypted files exist in your AxCrypt local cache folder and recent file list also.
You can stop the error messages by clearing the AxCrypt local cache by File | Options | Clear All Settings & Restart.
Now AxCrypt app will be opened like a freshly installed app. Then sign in with your AxCrypt account credentials.
Still, if you are facing any issues, please feel free to contact our support(firstname.lastname@example.org) with detailed information about the issue.