expired member cannot log-in

I have a member whose subscription [CBSubs] expired a year ago. He can no longer login ; a message says his record is blocked. I would expect that he would be offered the option to renew but this does not appear to be the case. I have now unblocked his record and assigned him to the standard free 'registered' CBSubs plan, but this just produces even more confusing messages; 'you have successfully logged in' [when he hasn't, or at least there is no sign that he has], and on trying again, an additional red message saying 'You cannot access the private areas of this site' and still no sign of a successful log-in.
Joomla 2.5.9 CB 1.9 CBSubs 3.0.0. GroupJive installed and Cb plug-ins for gallery, blog wall, profilebook
I suspect I have something mis-configured; any clue what it might be?

I notice that this user, among a small number of others has an entry in the cb_folderaccess field of the comprofiler table; can this be related?

You setup CBSubs not to allow free registrations. You also did not setup free lifetime plans to create subscriptions. So if a user doesn't have an active subscription they have no way to access your site. CBSubs warns you of this when configuring it this way within CBSubs > Settings > Global.

OK I'll test that; I confess that I have never been able to understand exactly what the tooltips for these settings mean. In fact, I have the first setting as No and the second as Yes. I also have a Free Lifetime plan in place which records users as Registered.

I have now set the first field to Yes and the second to No. The user is now showing with an expired paid subscription and a Free Registration plan. However, on log-in he still sees the same two messages.

OK I'll test that; I confess that I have never been able to understand exactly what the tooltips for these settings mean. In fact, I have the first setting as No and the second as Yes. I also have a Free Lifetime plan in place which records users as Registered.

That's precisely why we provide you with a 600+ page documentation.

I have now set the first field to Yes and the second to No. The user is now showing with an expired paid subscription and a Free Registration plan. However, on log-in he still sees the same two messages.

You need to unblock him as he's probably still blocked from last time then test again. They should still see an option to renew though, but your plan needs to allow renewals and be accessible to him (maybe access level on plan set too high?).

Well, I've just looked again at the manual, which I did read before setting up CB, and particularly this section, because I found the tips so confusing. It says at section 9.3.2.1 [in the version I have] that if I want to have created a free registration plan [which I have] then I might want to have this setting set to „No‟[which I did]. I then was told that the logical setting for the second field was Yes, hence my original configuration. The free registration plan has public access and Public User Group and allows new registrations.
It seems that in fact, if I want expired subscriptions to revert to the Registered CB Plan then I must set both fields to Yes. Is that correct? Certainly setting the first one to yes resulted in the User being subscribed to the free group.

Now I see where the problem is. The setting for 'Subscriber user group Access level' in the Free Registration Plan was set to 'no change of user group', which seems to have resulted in him being assigned to the Public Group, and hence blocked from logging in, though a message was displayed saying he was logged in. This looks as if it is a bug somewhere, whatever its cause.
Still, my user can now log on and can see the renewal option in his profile.
So all I need now is confirmation that the best setting for these free registration fields in this case is both set to Yes...

Your registration usergroup should never be Public. Edit this within Joomlas user manager options page and change it to at least Registered. If you don't need access protection on the free plan then you can simply get rid of it and allow free registrations without a subscription.