per admin i had my host look at ffmpeg instalation, but my customers are still having problem uploading video and if they do manage to upload a vid the thumbs are not generating,
my host is telling me there is a problem with htaccess file, this is what they wrote,

We have resolved the problem the conversion problem, but another has arisen. When we installed ffmpeg-php with php5 (we only had ffmpeg-php with php4) we were positive everything was going to work. When I visited that test page you had, I received an internal server error. I then removed the contents of home/showmeu/public_html/vshare/.htaccess, and it worked. It looked like there were many lines of code in .htaccess, and I didn't want to mess any other things up on your site, so I put them back. When you visit the test page, you will receive a 500 error, but if you remove the lines in .htacces, it will work. I suggest that you go through the .htaccess file and try and figure out what is causing the error.
can someone tell me what this means, and how i should go about fixing it.

thanks