Already problems with Imovie
Hi, I have problems to share videos on Youtube and to import file avi . But also with Mp4 I have problems ... my MBP mid 2014 ( 16 Gb Ram) freezing
MacBook Pro 15", macOS 10.14
AVI files are not supported in iMovie. They need to be converted to Mp4/AAC. Likewise not all Mp4 is supported by iMovie. It needs to be Mp4/AAC. Files in another format can be converted by the free download Handbrake or VLC.
For the freezing problem, try restarting your computer and opening iMovie while holding down the Option an Command keys, and selecting to delete preferences in the box that appears. iMovie will open in a new library. Reopen your old library to get back to your projects. Now see if you can import files in a supported format and export to You Tube.
If the above doesn't work, try booting up in Safe Mode (see Finder Help menu item for directions) and, after everything loads, immediately shut down and reboot in normal mode. See if that clears out any conflicts that might be causing the freezing or export problems.
-- Rich