Firefox: complete deadlock when asking to save the file.
Edge: "Save" sometimes works, "Save as" does not, and breaks something ipc wise, the browser cannot be closed, tabs cannot be closed, until you terminate and restart the edge parent process.
When cancelling the download to remove it from the list, the same thing happens.
This is because of a flaw in AxShlExHlper
This same flaw results in AXShlEx.dll and AXShlEx64.dll hanging Regsvr32.exe when trying to unregister and register these dll's.