I can test when I get a chance, but...
Did this work fine before and just start happening?
As a test, not a solution, does the installer complain if you try to install to "D:\Apps\Opera Test"?
As a test, does the installer complain if you do?:
OperaSetup.exe --allusers=1 "--installfolder=D:\Apps\Opera"Any difference with?:
OperaSetup.exe --allusers=1 "--installfolder=D:\Apps\Opera" --silent=1https://www.reddit.com/r/operabrowser/wiki/opera/installer_commands/.