Ok. Cache issue. Cleared cache, and back in play (almost)
@Eric-Ladner No, it doesn't upgrade the plugins... or I should say, it didn't used to.
More recent versions of NodeBB call ./nodebb upgradePlugins as part of the upgrade process, and that will upgrade plugins (to whatever version nbbpm says they should be upgraded to)...
However, those plugins that aren't registered with nbbpm won't be touched by ./nodebb upgradePlugins.
I resolved this. I had an invalid code. Thanks for the help.
as temporary solution added to custom.css:
@julian 3Q，QQ single sign-on configuration page is ok, but I found another problem.
i can't find the button of qq sso in the login page.
I found "CUSTOM HEADER" is not working while “Use Custom css” is checked!