Hello Henry Liao,
If the file is actually damaged to this extent, no, it can’t be fixed. The data is just not there to decrypt it.
But we have a feature called Try Broken File. You can able to decrypt the corrupted AxCrypt encrypted files by navigating the menu File | Options | enable Debug from the AxCrypt app.
Now you can able to see the Debug the menu in the AxCrypt app. From the debug menu you have to select Try Broken File.
Now you will be prompted for file selection. Select the corrupted encrypted file and then AxCrypt will try to decrypt the file. If successfully decrypted, then you can able to see the decrypted file in the location. Otherwise, AxCrypt can’t able to decrypt.
After doing try broken file also, you are getting the same exception, then the file might be corrupted. Sorry to say, you can’t decrypt the same.