You don’t have permission to save the file “988BF072-A4B9-4ABE-9FB8-2F3A8EBC2E2C” in the folder “CoreSimulator”

This folder exists.

I've tried moving it to the trash (it reappears and then this message pops up).

I've reset all permission to all enclosed folders to R+W.

I've repaired permissions on my drive.

Plugging in a real phone works fine (probably not relevant). enter image description here

Solution

Turns out the actual folder for the log file didn't exist.

When looking in Console.app, filtering on CoreSimulator, I saw this:

3/15/15 9:50:52.840 AM iOS Simulator[7291]: Error opening /Users//Library/Logs/CoreSimulator/iOS Simulator.log

When I went to the Logs directory, CoreSimulator wasn't there, so I:

sudo mkdir CoreSimulator
sudo chown <user>:staff CoreSimulator
touch CoreSimulator/iOS\ Simulator.log