Tried to install os x el capitan and received this error message INSTALL_ERROR_DISTRIBUTION_SIGNED_BY_APPLE

I have the exact same problem, MacBook Pro 2011, unable to sync new iPhone 6 with iTunes and that exact message under /var/folders/ is not coming up for me either.

Worked like magic, thanks so much!!

Thank you SOOO much!!!! I'm so computer illiterate. At first this was a bit confusing until I read the other comments but I am finally able to get X !!

This worked for me as well! Thank you!

create a test user account and log into it to do the app download/ install or OSX upgrade. should work every single time. yall are welcome!

im sure there are other ways of fixing / working around this issue, but i consider this the most basic and novice user friendly way to solve it easily and quickly

Hello

you guys look like you have helped a lot of people. could you be so kind to answer me a question. my macbook early 2008 13" is up today for memory which i installed has 6gb and the storage was upgraded as well i still have 150.+gb left. i have tried to do a clean install as well for el capitan and i get the same error. not able to do anything. what other suggestions do you have. i went to console and didn't find any of your folders you suggested either. any other suggestions would be helpful thank you

Holy.... It works! That's genius!
Thanks a bunch!