In About this Mac it shows that the OS is Yosemite but the version number is 10.90. Is this normal? I thought Yosemite is 10.10, and Mavericks was 10.9.

OS X Yosemite Version 10.90

  • 1
    Your Installation did not go so well :)
    – Ruskes
    Nov 27, 2014 at 17:05
  • 1
    10.90 would appear to be one of the beta builds. 'fix' seems to be to install the release over it.
    – Tetsujin
    Nov 27, 2014 at 17:08

2 Answers 2


Download the latest Yosemite installer from the Mac App Store but do not install it.

Copy following in to your Terminal to verify the downloaded Yosemite file is correct:

shasum /Applications/Install\ OS\ X\ Yosemite.app/Contents/SharedSupport/InstallESD.dmg

Wait for a minute for it to calculate. The result for the previous version should be:

eebf02a20ac27665a966957eec6f5e6fe3228a19  /Applications/Install OS X Yosemite.app/Contents/SharedSupport/InstallESD.dmg

And for Yosemite Download as of Nov. 27 the result is:

a673c2c6d967f4da2934b7d6cf3736936970b194  /Applications/Install OS X Yosemite.app/Contents/SharedSupport/InstallESD.dmg

Proceed with Install.

  • I'm getting: a673c2c6d967f4da2934b7d6cf3736936970b194 /Applications/Install OS X Yosemite.app/Contents/SharedSupport/InstallESD.dmg, when trying to install it prompts "This copy of the “Install OS X” application is too old to be opened on this version of OS X."
    – AndPy
    Nov 27, 2014 at 18:52
  • hmm, my download is from Nov 7 !
    – Ruskes
    Nov 27, 2014 at 18:54
  • mine is from today, but anyway, I can't install it.. ideas?
    – AndPy
    Nov 27, 2014 at 18:54
  • I am re-downloading it to double check. another 40 minutes to wait to confirm. Your checksum is strange for now, do not use it.
    – Ruskes
    Nov 27, 2014 at 18:58
  • Wow, I really appreciate that :)
    – AndPy
    Nov 27, 2014 at 19:03

Mmmh, maybe you've changed it yourself and forgotten about it?

Changing OS X version to 10.90 has been suggested to solve some compatibility issues, e.g. with Matlab (see MATLab crashes on launch OS X Yosemite).

To change it back to 10.10, type the following in a Terminal window:

sudo nano /System/Library/CoreServices/SystemVersion.plist

then change the value under 'ProductVersion' to 10.10 or whatever version you fancy.

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