How to fix >>> "The encoder timebase is not set" ???

[ICDedPPle]

I finished my work in video editing with MP4 file and some another media.(sound and image)
I want to render it to MP4 file. But it show up The encoder timebase is not set.....what happen??
I check the fps, All is same (60 fps...I select custom to check and it's still 60 fps)
What I can do? I work with MP4 file because I can not open AVI file (window10 missing code 0xc00d5212)
.
I do not want to rework at all. :((
Please Help T___T

[ICDedPPle]

OK !
I'm loaded version 2.8 already and everything is back to work!
and now I can work with AVI file.

If someone have a same as my problem. You can do like me. >> load new version :)

[hihah]

ok ..

[会说话的草丛]

……ok