Well, I’m no expert and apologize for sounding like one. Since the ‘80s I’ve seen computers do crazy things, yet have learned many tricks along the way. I don’t know why it works, but the removal and reinsertion of a file deceptively, has saved me many times with other applications. I can only guess something in the encryption process went wrong. If you can’t open the file at all, it’s not recognizing the .dat file name that was generated. Then, too, if it opens and all you see is encryption then somewhere the format on which the original was written unintentionally affected the procedure. Believe it or not, on a weak file encryption that has a unique extension, the contents can be copied and pasted to Notepad and be read. I tried this with one of my files and found the text to be of Chinese. In translation, a few names popped-up along with other words I did not write. But, I must point out, that if I knew of a way to read your files it would be unethical and illegal to post. However, keep the files and play around. I’m 66 and over the years I’ve seen people with little knowledge accidently solve complex problems.
BTW, I mentioned encrypting passwords with a letter that cannot be typed. This means with the use of standard fonts enter a key-code. When you look at a character map each block with a letter outside the normal keyboard has a code. Some blocks are empty but have a code. For example: in a situation where you cannot separate two words with a space, you can enter a blank character (no-break-space): abbybritton would be entered, abby Alt+0160 britton = abby britton. But, look on the bright side. Testing the encryption first before you dismiss the original is a good idea. And in a truly severe case, I still transfer data to a disk only I know of its whereabouts. Good Luck! 
