I just tried to update KLAX from 1.1.1 to 1.1.2 via the IniManager and the install repeatedly failed with a red box stating scenery_config.json could not be handled or something to the effect once all files were copied. When I went to check the installation folder KLAX resides in I found the file to be present, but flagged read-only in the file properties. After manually changing the flag and restarting the installation process, all went through without a problem.
Maybe some of you get the same error and appreciate the workaround.