500 error in manage > posts paging

We have upgraded to the latest version of the blog and now when we go into the manage > posts menu the list of posts is around 30 over 3 pages. The first 10 posts display in the table correctly. There are 3 page links at the bottom of the post list table.
Clicking either page 2 or 3 gives a 500 error and we get the following error in the DNN log:

2022-05-12 09:09:13,019 [Orchid][Thread:11][ERROR] DotNetNuke.Services.Exceptions.Exceptions - DotNetNuke.Services.Exceptions.PageLoadException: The GridView 'grdPosts' fired event PageIndexChanging which wasn't handled. ---> System.Web.HttpException: The GridView 'grdPosts' fired event PageIndexChanging which wasn't handled. at System.Web.UI.WebControls.GridView.OnPageIndexChanging(GridViewPageEventArgs e) at System.Web.UI.WebControls.GridView.HandlePage(Int32 newPage) at System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) at System.Web.UI.Page.d__523.MoveNext() --- End of inner exception stack trace ---

Can you advise what the issue may be and a possible solution?
Regards
Roger