Failed to Attach to Process ID Xcode

Resetting the content and settings in the simulator worked for me. This is available in the "iOS Simulator" menu.

go to the Product menu and find the Edit Scheme menu there.

While in Edit Scheme window, select the "Run" option on the left hand side of the screen and then on the right hand side, change the debugger from LLDB to GDB.

I experienced the same problem, and after a while I found out that it was due to the fact that my XCode project included a Folder Reference to a folder named Resources.

It seems that XCode doesn't like that name.

Just removing the folder reference or renaming the folder solved the issue.

TWO METHODS

Method 1 : Inside the folder Application Support -> iPhone Simulator -> In the each simulator version of iOS -> Applications -> Delete all the files present here.

Now go to Products -> Clean

Now run it on any simulator and it will work.

Method 2 :