Updated mono and now I get this.

[d3null]

Updated mono from 2.11.4 to the latest stable 5.4.1.6 (long overdue) and now when I access the site I get this:

 

Application Exception
System.IO.FileNotFoundException
Could not load file or assembly 'System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies.
Description: HTTP 500.Error processing request.

Details: Non-web exception. Exception origin (name of application or object): Telerik.Web.UI.

Exception stack trace:
 at Telerik.Web.UI.GridDataSourceHelper.CreateGridEnumerable (Telerik.Web.UI.GridTableView owner, System.Collections.IEnumerable enumerable, System.Boolean caseSensitive, System.Boolean autoGenerateColumns, Telerik.Web.UI.GridColumnCollection presentColumns, System.String[] additionalField, System.Boolean retrieveAllFields, System.Boolean enableSplitHeaderText) [0x0001b] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at Telerik.Web.UI.GridDataSourceHelper.GetResolvedDataSource (Telerik.Web.UI.GridTableView owner, System.Object dataSource, System.String dataMember, System.Boolean caseSensitive, System.Boolean autoGenerateColumns, Telerik.Web.UI.GridColumnCollection presentColumns, System.String[] additionalField, System.Boolean retrieveAllFields, System.Boolean enableSplitHeaderText) [0x000ca] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at Telerik.Web.UI.GridTableView.get_ResolvedDataSource () [0x0004f] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at Telerik.Web.UI.GridTableView.CreateChildControls (System.Collections.IEnumerable dataSource, System.Boolean useDataSource) [0x0000a] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at System.Web.UI.WebControls.CompositeDataBoundControl.PerformDataBinding (System.Collections.IEnumerable data) [0x00018] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.WebControls.DataBoundControl.InternalPerformDataBinding (System.Collections.IEnumerable data) [0x00017] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.WebControls.DataBoundControl.OnSelect (System.Collections.IEnumerable data) [0x00013] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.DataSourceView.Select (System.Web.UI.DataSourceSelectArguments arguments, System.Web.UI.DataSourceViewSelectCallback callback) [0x0001d] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.WebControls.DataBoundControl.PerformSelect () [0x00032] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at Telerik.Web.UI.GridTableView.PerformSelect () [0x00007] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at System.Web.UI.WebControls.BaseDataBoundControl.DataBind () [0x00000] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at Telerik.Web.UI.GridTableView.DataBind () [0x000a1] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at Telerik.Web.UI.RadGrid.DataBind () [0x0003a] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at Telerik.Web.UI.RadGrid.AutoDataBind (Telerik.Web.UI.GridRebindReason rebindReason) [0x00415] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at Telerik.Web.UI.RadGrid.OnLoad (System.EventArgs e) [0x00040] in <30c1931d6456454dbb0f48f5b0851c34>:0 
 at System.Web.UI.Control.LoadRecursive () [0x00028] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Control.LoadRecursive () [0x0005a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Page.ProcessLoad () [0x0004a] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Page.ProcessPostData () [0x00047] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Page.InternalProcessRequest () [0x001a1] in <285fcaed03ee42169c0cbd7bda90aaab>:0 
 at System.Web.UI.Page.ProcessRequest (System.Web.HttpContext context) [0x0005f] in <285fcaed03ee42169c0cbd7bda90aaab>:0 

 

 

Any ideas? (I've also opened a ticket)