windows explorer > right click on the file > encrypt: explorer closes — AxCrypt app run in the background and opens in your system. Please sign into the AxCrypt. After sign-in your files will be encrypted.
The error message states, the encrypted file which you are trying to open File does not exist in the location. It might happen because of the files/secured folder are not available, temporary system files, network not available.
Please check whether the encrypted file is present in that location or not. If yes, select the files to open. Now AxCrypt will open the same.