I've been trying to find something on this all month and am so frustrated there doesn't seem to be anyone else having this problem. After the recent Kindle Fire update I haven't been able to use any files currently converted with Calibre. Let me explain this...
Any files I made several months ago will read in my KF but files I've tried converting in the last month will not read. That is to say, I can open them but within seconds they crash and I'm returned to the main screen. Things that cause the crashing are changing the font size or background. Once it crashes then I can never get it to work again. The file will only stay open for a few seconds.
I tried completely removing calibre and using an older version of the program but even that is not working despite that it's the same version that I used to make the old files that do seem to work.
I hope I explained this clearly enough, if not please ask me questions and I'll do my best to fill in any blanks. This is very frustrating as I do a lot of conversions and am now unable to read any of the converted books done this month. I'm guessing that it has something to do with the KF update but as I am not an expert in this area I cannot be positive. Is there anyone who can help me with this??? I would so greatly appreciate any help.