Release Notes for v42.11.15

Fixes

Fixed a crash on Linux at startup or on theme change with GTK modules loaded. #55015
Fixed an issue where clicks posted to a background app were dropped on macOS. #54906 ^{(Also in 43, 44, 45)}
Fixed net.fetch and session.fetch failing permanently with net::ERR_FAILED after the Network Service process restarts. #54925 ^{(Also in 43, 44, 45)}
Fixed utilityProcess dropping messages posted with process.parentPort.postMessage() right before the process exits. #55000 ^{(Also in 43, 45)}