sometimes this happens when lots of effects are stacked on one clip, or just one effects is on a file like a PNG or something obscure that premiere pro is not used to working with. this also happes when lots of audio editing has occured, so what i always do is export my audio before i render, and just have one finalized audio track in the timeline, THNE i render.
also, export using Adobe Media encoder instead of AVI, that way when it stops you will still have the file…whereas when you export to AVI, the file is deleted if it doesnt finish. If you use Adobe Media Encoder, you will can watch the part it did export up until the problem point and find out which frame(s) are giving you trouble, and just go in and modify those.
I have found that just restarting premiere many times will let me export…OR just render that one problem segment by itself (razor/cut it our of your main sequence to its own sequence, render it to highquality AVI or whatever format you are working in, then put that rendered piece back into the timeline…sometimes i have to render 7-8 AVI pieces for my projects, then put them all together because I use lots of 3rd party plugins that premiere doesnt like when having to do one long render.
::: Connor