Disk Partition Format:
iMovie project must be created/opened/modified on a Mac OS Extended or Mac OS Extended(Journaled) partition. If not, please move the project to a right partition .
QuickTime add-ons:
Incompatible QuickTime add-onsmay cause iMovie crash, for example Divx, Flip4Mac, or 3ivx, eitherupdate them or delete / move these add-ons to other folder.
These add-ons may reside on /Library/QuickTime folder which will affect all users, or on users' ~/Library/QuickTime folder which will affect this user only.
Third-party iMovie plug-ins:
Please update them or delete/move them to other folder.
They may reside on /Library/iMovie or users' ~/Library/iMovie folder.
Disk Space:
It may ask for at least 2GB or more free spaces to edit a iMovie project. Depends on your project size, it may ask for more.
In-compitable software issues:
The most easy way is create a new user, but it may not a option in some scenario.
Permission:
This may be the issue. Don't know how to fix permission? Ask administrator.
Conflict Version:
If you updated it to a newerversion before but downgraded back, this might be the issue. The oldversion will not read the new version plist file correctly. So deletethe plist file may be the choise.
All related plist files: ~/Library/Preferences/com.apple.iMovie*.plist
~/Library/Preferences/com.apple.quicktime*.*.plist
Font Related:
If you migrated your user profile from a old system, this might be the issue:
Delete/move ~/Library/FontCollections folder.
This picture is showing this issue:
iMovie和iMovie HD的问题解决
磁盘分区格式: 这个软件要求它的文件应该保存在Mac OS Extended格式的分区中,如果不是,或者移动到一个符合要求的分区,或者找到一个无用分区格式化成该格式。注意,Mac OS Extended (Journaled)分区格式也是支持的。
QuickTime的附加软件:
QuickTime的附件附加软件很有可能造成iMovie的运行问题,比如Divx, Flip4Mac, or 3ivx等。解决办法,升级这些附加软件,如果找不到/无法升级,可是移动或删除他们, 一般来说,它们储存在下面的目录里面:/Library/QuickTime或者是用户的~/Library/QuickTime