Q: will imovie 9 work in Sierra?

I have no idea but since it already has problems running under El Capitan I would not set my hopes high.  If you want to try, make a bootable clone of your present operating system on an external drive or separate partition before updating so that you can go back to it if Sierra gives problems.

Geoff.

When I try to launch iMovie 9.0.9 on Sierra it will open the main application window and crash as soon as I try to move the cursor.

Sounds as though you have the answer already, but just to add that your iMac appears to be pre early 2009 and as such is not compatible with Sierra.Needs to be late 2009 or later.

I have had no end of problems with iMovie and operating systems.  I have left my machine operating on Yosemite with iMovie 9.0.9 for mostly date and time reasons. Simply put, El Capitan would run 9.0.9 but the date and time was continuous. IE if you shot 4 hours of video, the date and time would not be reflective of when the video was shot.  The time would just run from 12:00pm onwards, despite the fact the video was shot over 4 hours.  I had to constantly adjsust the date and time by 10 hours (Australia) regardless of my system settings or my camera settings. Very frustrating . iMovie 11 was also painstakingly slow on El Capitan. 

Tonight I upgraded to Sierra, then in a moment of weekness tried the latest iMovie.

  Apple finally seem to have got it.  No date and time adjustments, real date and time reflective of when the video was shot.  iMovie 11 runs fast and so far no problems at all.  ONLY 8 F***ING YEARS TO GET IT RIGHT.  I may never upgrade my computer again.  However, be mindful of your own computer specs, but I'm happy finally. 

P.S.  I movie 9 also ran fine on Sierra.

P.S.  I movie 9 also ran fine on Sierra.

Would you please try,  if iMovie 9.0.9 is still running correctly on Siera, after you opened your iMovie Libraries in iMovie 10.1.2 on Sierra?

Hi Leonie,

Just checked.  I am able to run both 9 and 11 and both are working fine.  9 took a while to start ONLY the first time it was opened after the Sierra instal but now opens as fast as 11.  I have checked most features (date/time, sharing, clip splitting, audio etc) and all seem to work ok.  Sorry you are having troubles, let me know if there is anything else I can help you with.  Having said all that, I was never able to run 9 under El-Capitan?

Just to be clear, my version of "9" is 9.0.9 build (1795)

Having said all that, I was never able to run 9 under El-Capitan?

Under El Cap i could occasionally open it, but it kept  crashing after working a bit.

Thank you for the added info.

I tried a few times more, and now iMovie 9.0.9 launched successfully.  Never say no! But I am still not trusting it fully. The Photo Browser can still not show the Photos Library.