Hi @fevered
Thank you for your quick reply!
I have isolated it to bee the woo-vipps plugin. The plugin got disabled in recovery-mode in wordpress, and the site/woocommerce/payportal seem to work fine. The source of trouble has to be the vipps-plugin then.
At the same time I have notified support at Vipps for them to dig into this, in the faith that they would be interested in fixing this sooner than immediately.
In the overview of plugins this plugin now says it has not been tested against the current version of wordpress, so I believe this has a connection to the issue at hand.
Thanks again for your reply.
Br,
Sturla