Progress not showing when updating docset

Tried with both 0.3.1 stable and latest master running on Windows 10 x64. Trying to update Mono.

Downloads 100% but then looks like it's complete when in fact it's actually installing the new docset. I get the message "Please wait for all operations to complete" if I try to close the dialog until it's finished installing (confirmed by checking CPU and disk activity (seems to work a lot quicker with Defender disabled too).