Apologies for the delayed response.
I think, you manually clear system local cache(%LocalAppData%\AxCrypt(C:\Users\’User Name’\AppData\Local\AxCrypt) or might clicked the Reset button in the sign in password dialog . That button is used to reset the AxCrypt account data in the locally installed AxCrypt app. That means, it will clear all the local contents cache of the AxCrypt app ans restart the app like a freshly installed one.
Then you have to provide your account email address and password again to sign in to the AxCrypt app.
Please sign in your boss AxCrypt emails address and credentials in AxCrypt app. Now open/decrypt the Encrypted files without any issue.
If the above does not help,Please provide more information about the issue and write a mail to firstname.lastname@example.org . you can send a screenshot showing where the problem is, it often helps us understand.