The S2 columns in the Dashboard Users list are empty (Registration Date, Last Login Time, etc.). The data is there: sorting asc and desc work …
S2 columns empty in Dashboard user list
That looks like a plugin conflict.
Deactivating all your other plugins and switch to a default theme.
If s2Member columns now display as expected, you had a conflict before. You now need to change back to your own theme and test again. If the problem recurs, the conflict is with your theme.
If the problem does not recur, the conflict is with another plugin. You now need to turn each plugin on, one by one, and re-test after each activation until the conflict recurs. Then you’ll know the culprit.
Had already tried with all plug-ins deactivated and was same; had not tried
default theme. All OK with that … how on earth to track down a bug in a
theme? Need a new one anyway … thanks.
Wow, that’s a very unusual bug for a theme! I wonder why it’s affecting the back-end; themes should really just focus on the front-end.
Anyway, thanks for reporting back!