The latest version of Logic Pro 9 is v9.1.8 which does work for some people under Yosemite.....
If you have the app store version of LP9 then software updates will provide a means to update to that latest (and actually last) version
if you have the Logic Studio (DVD) version of LP9 then you will need to use the file provided in this link....
Logic pro 9 free download - Apple Logic Pro X, Adobe Acrobat 9 Pro Extended, Adobe Acrobat Pro DC, and many more programs.
If you find that LP9 9.1.8 does not fuction well for you on your system under Yosemite then there is little you can do except to either;
1) Roll back to a previous OS X + LP9 setup that works well, using your backups....
or...
2) Purchase Logic Pro X..... via the app store.
Note: There is no means to update/upgrade LP9 to LPX as such.. You simply purchase the full version from the Mac App Store. The cost to do so is the same, or much less than it used to cost to upgrade from previous versions of Logic Pro to newer ones.... From LP8 to LP9... for example... used to cost $499 and then later $199
Aug 15, 2015 1:25 PM