Exported video is just white and without sound


as always I tried to cut, compress and then export. The first video > black - no sound and the next one > white picture - no sound. The file size is the same but the videos are useless. I don’t know what happened and what to do?

We don’t know what happened either.
What are your computer specifications?
What operating system are you running?
What version of Shotcut do you have? Latest is 18.06.02

What file formats are you working with?

We do not know either. This is a useless post. Next time try providing useful information.