When trying to install the latest version of iTunes I get an Alert "This software is not supported on your system." I'm running OS X Yosemite Version 10.10.5. Any help?

Open App Store , select Updates.

If you see a Security update available, I suggest you to apply it. If a restart is required, do it.

Then still from App Store, if you see an iTunes update available, I suggest you to apply it.

Hi,

Yosemite should be OK for the latest iTunes. iTunes - Download iTunes Now - Apple

You might try downloading it from the above link.

Also, you could try reinstalling Yosemite with the combo updater. Download OS X Yosemite 10.10.5 Combo Update

Did you get this last version of iTunes from App Store?

For your information (I know this won't help you now)

I have a MacBook Pro running Yosemite 10.10.5,

and I upgraded to iTunes 12.7.2.60 (the latest version) this night without any error

message. This version of iTunes is running perfectly on this version of the OS.

Could you check that the time is correct on your Mac?

Many updates can fail when the time is wrong (because of limited validity of softwares)

but the upgrade software (App Store) won't tell you this is the origin of the failure (because this would be much too complex for many users and would give a very bad image of Apple).

OK if you don't want to reinstall the OS. But you should look up Limos' advice about the security update. Those updates are found at the App Store. Click on the Updates button and you should get a list of available updates and updates installed recently. You may also find the iTunes update there.

Have you run the latest security updates? Another person had this problem and that was the solution.

Do you mean that there was a failure in dependancy checking between the last security update and the last iTunes update?

You're welcome!

You're welcome

😎