You sure haven’t given us much info to go on, for us to assist you.
And why in the world are you using and querring video joining software?
Forget about rendering in small segments, that’s a waste of time.
What specific errors are you talking about and whats the render settings
and format you are rendering out to? Whats the format of the video you
have on the timeline? etc, etc, things like that.
Have you tried rendering to another format or tried disabling your GPU, need
more to go on.
Steve Rhoden (Cow Leader)
Film Maker & VFX Artist.
Owner of Filmex Creative Media.
Samples of my Work and Company can be seen here:
https://www.facebook.com/FilmexCreativeMedia