Upgrade to Digikam 8.4 has failed

Since upgrading from 8.3 to 8.4, Digikam no longer functions, I just get a blank window with the Digikam logo in top left corner. Anything I can do to recover my existing installation?

Thanks

(Windows 10 22H2 )

Any suggestions for any other sources of help with my failed upload. Have sent them messages via Twitter and Facebook but no reply as yet. Thanks