Some more info on this issue... the problem is that accessing any of the blogs on my site fails via the ViewList.aspx address that the pager uses, e.g.
https://mysite.com/Blog/ViewList.aspx?pageid=143&moduleid=145&pagenumber=2
The pageid and moduleid are correct for this particular instance, and the blog(s) have not been moved around within the site.
Accessing posts via the Categories and Archive links works fine, e.g. https://mysite.com/Blog/ViewArchive.aspx?month=3&year=2025&pageid=143&mid=145
The error when accessing via ViewList.aspx is as follows:
Sorry, you are not allowed to view this content. If you have questions about your permissions, please contact a site administrator.
Either you are not currently logged in, or you do not have access to this page within the site. Please contact the site administrator to obtain access.
Return to Site Home
The message is spurious.
The blogs were all protected by View Roles, and on protected pages, but I've checked removing all restrictions and the above error still occurs, whether I am logged in or logged out.
There's nothing in the System Log when this happens.
Is this a mojoPortal bug in 2.9.1, or something wrong with our instance, and if so, any thoughts what that might be?