Unable to Edit Imported Jpeg files.

Question

I'm currently using iPhoto 9.6 and OS 10.10.   I have created jpg stills from .mov projects using QT Pro and imported them successfully into a previous version of iPhoto where I was able to crop them and make rudimentary color and exposure adjustments.  With the new iPhoto 9.6 I cannot.  I get an error message "Image Cannot Be Edited.  The original format is not supported."
So I am assuming the only way to edit these imported jpegs is to open them in Lightroom or Photoshop make my adjustments and then attempt to re-import them into iPhoto or maybe just stop using iPhoto all together for this kind of file?

Answer 1

Yes "master" copies of files - those located in the iPhoto >>package contents >> Masters folder organized by import date - once they have been edited from within iPhoto (exposure corrections, cropping, straightening, etc) become the master copies.
Bewilderingly vague. They are the masters. They are never edited. The photos are edited and the results recorded in the SQL database. The never "become the Master copies". They are the Masters and never become anything.
To prove this I have selected a master file from with this directory and created a copy of it on the desktop where I gave it a new name, then re-imported it to iPhoto and re-opened it there.  It is a virtual clone of the original edited file - edited from within iPhoto save for its name - an "edited master". 
If you made a copy of a Master then it's not a virtual clone it's an actual clone. "It is a virtual clone of the original edited file" Huh? What's an "original edited file"? It's a Master or something else? Which is it? There is no concept in iPhoto of 'edited Master'. There are Masters. That's the file as imported from your camera. It is never edited. End of story.
Subsequently from within iPhoto I have chosen the original photo - the one that had been modified to begin with - and reverted this file to its original version.  So then I had two masters of the same shot - one edited and one in its originally imported state.  Why did I do this (and originate this post)?
No you didn't. You had two masters to begin with and thereafter you had two masters at the end. When you reverted to original all you did was delete the edit decisions for the database and destroy a preview. In no case was the Master touched.
The terminology is important because it explains how the app works. You're conflating photos (which are edited in iPhoto) with files (which are never edited in iPhoto), all photo edits are virtual until baked in on export. That's why the concept and the term Master is important. Edited Master means nothing, Master of an Edited Photo does, but that's a different thing.
Because I could not re-edit or export these affected photos unless I first re-imported them to iPhoto by either locating the original files from storage media or making copies of them from iPhoto's package contents>>masters folder as above and importing them back into the iPhoto library.  Once I did this - there were a lot of these affected files - I could edit and export to my heart's content.  Remember, these files were modified from within earlier versions iPhoto itself.  Yes, some files had been converted to jpegs from original PICT exports out QT Pro using Photoshop Elements.
Because your database was corrupted. It has nothing to do with Masters/Versions or anything else. It was broken.
How do I explain this apparent corruption of the iPhoto library database?  Disclaimers to the contrary, I put the onus on having to convert the db every time there is an app iteration which is sometimes coupled with an OS upgrade (like with Yosemite).  I suspect that the file metadata is susceptible to corruption during these upgrades.  It is the only variable in an otherwise static and stable environment that could possibly result in library corruption short of hardware failure.
That's one possibility. Here are some more: anytime the app is interrupted writing to the database - by a crash, hang or even a power surge, bad blocks on a disk - there are many possibilities..
And again, there is no need to convert the db "every time there is an app iteration". There are updates when it is not necessary. And, as I keep on saying, OS upgrades make no difference. It's app upgrades only.