My operating system is OS X Version 10.6.1.
The error message I receive is:
The document “opening doc5 4x3.mov” could not be opened. The movie is not in a format that QuickTime Player understands.
You may need to install additional software to open this type of file.
The Tell me more button takes me here:
http://support.apple.com/kb/HT3775?viewlocale=en_US
What do I do?