format factory fails to complete all conversions?

[extent]

Format factory has stopped working. The program fails to convert videos to MKV and MP4. At 98% the program will hang during conversion and eventually state 'failed'. I have noticed that after a reinstall, the issue still remains, with the added bonus of no longer being able to drag videos from windows into the program in order to be converted. Perhaps both of these issues are related to permissions and not being able to write, but even with all protective software off, changing output directory and running the program as an administrator, the problem is still there. I am using the latest version of the program, v301. Any ideas on what could be causing it? I am using the codecs that installed with Format Factory. thanks for any help

update - to fix it for mkv and mp4, I had to make sure that audio in 'output setting' for each video was disabled, as having the audio enabled when an original video did not contain audio, would give the error. Im not sure if these errors only happen on my machine and if the program should just ignore it (if the audio setting is enabled for a video without audio), instead of failing at the end of each conversion.