kwallet wallet gone kde4 to kde5

I've just updated my slackware-current install and seemed to go smoothly except kwalletmanager5 does not show my old wallet from KDE4. I can see the .kwl file is there and the .salt file too. I tried the File->Import a wallet but it did nothing, as in it didn't open a window or spit out a message on the command line from which I launched kwalletmanager5. A search on this forum yielded no clues and a wider search shows I'm not alone in this problem but none of the fixes I found worked for me.

Any suggestions gratefully received.