customer can't log in

Hi,

I have this one customer who keeps saying he can’t log in. The logs show him as logging in but he disputes this. He says he hits the login button and the loading disc keeps spinning, and nothing happens.

I doubt this is a problem with S2Member, but am frustrated why I can’t figure this out. I tried replicating it…hit login and then, before it refreshed, I quickly clicked another link and I was logged in. But he says this is not happening with him.

Any idea as to why this is happening, would be appreciated.
Thanks

https://www.ads-software.com/plugins/s2member/