The first step would be to completely uninstall both Quicktime and iTunes. You may also want to just uninstall MC12 too for good measure (but choose
not to delete your registry settings or library). Then
reboot, and
download Quicktime 7.3.1 (and iTunes if you want). Follow these instructions to install it in the "least evil way possible":
http://www.codecguide.com/quicktime_installation.htmLastly, assuming that all went well, reboot again and then reinstall MC using the current build. So you know, the newest version isn't always found by the auto-updater. They generally only update those builds once in a while when a very stable release comes out, mainly to avoid annoying people with constant notifications of updates. JRiver releases a new version of MC about once per week. The newest version can always be found "stickied" in a thread at the top of this forum. You can imagine that some people would get annoyed if it told you there was a new version every single week (and sometimes twice on Mondays)!
If this doesn't help, come back here and let us know, and please enable logging in MC. To do this, go to
Help --> Logging. Check the
Output to a log file box, then in the
Types of Events box, check
all of the options. Click OK to save and restart MC. Then reproduce the crash and re-open MC. You can then email the log files by going back into
Help --> Logging and clicking on the "Click to email log files" link. I'm not sure who to tell you to email them to (perhaps someone from JRiver can post back and tell you where to send them if we get to that stage).