Hello, I have a 2015 Macbook Pro running El Capitan 10.11.6. The laptop is connected to an old Thunderbolt monitor that works perfectly but will not tolerate software updates for whatever reason. The way around that was to . . . not update the software for the monitor. However, I accidentally did so one day and now I am faced with an error message every time I boot up the laptop that tells me that the Thunderbolt display update failed to install and do I want to retry or cancel? I need to get rid of that error message and believe the path forward is to delete the update file. However, all of the posts I have found regarding the location of update files point to locations that don't exist in El Capitan. I've found a Firmware Update folder in System > Library > Core Services > TBFirmwareUpdate that certainly seemed relevant, but OSX does not permit me to delete the .bin files contained in the folder. I would appreciate help in finding that update file and any special instructions that might be necessary to delete it so that the damn error message that I see every time I boot up goes away. Thanks so much.