I've been using a C1 WebChart in a 4.5.5 portal with no trouble. When I updated to 4.6 it broke immediately. If I drop a chart, as a test, into a clean, freshly built v4.6 project in the Starter Kit, I get the same message. It seems like there might be a module injection issue of some sort?

Any thoughts?. All my other stuff seems fine after the update.

This is the error message: The string parameter 'tagPrefix' cannot be null or empty. Parameter name: tagPrefix

Event Log Entry

AssemblyVersion: 04.06.00
PortalID: 0
PortalName: s
UserID: 7
UserName: D
ActiveTabID: 100
ActiveTabName: Yield Curve
RawURL: /DNN/Data/InterestRates/YieldCurve/tabid/100/Default.aspx
AbsoluteURL: /DNN/Default.aspx
AbsoluteURLReferrer:
UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; InfoPath.2; .NET CLR 1.1.4322)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 2676c480-a4e4-4e05-b9a5-813b8ee3262b
InnerException: The string parameter 'tagPrefix' cannot be null or empty. Parameter name: tagPrefix
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Web.UI.TagPrefixAttribute..ctor
StackTrace:
Message: DotNetNuke.Services.Exceptions.PageLoadException: The string parameter 'tagPrefix' cannot be null or empty. Parameter name: tagPrefix ---> System.ArgumentException: The string parameter 'tagPrefix' cannot be null or empty. Parameter name: tagPrefix at System.Web.UI.TagPrefixAttribute..ctor(String namespaceName, String tagPrefix) at System.Reflection.CustomAttribute._CreateCaObject(Void* pModule, Void* pCtor, Byte** ppBlob, Byte* pEndBlob, Int32* pcNamedArgs) at System.Reflection.CustomAttribute.CreateCaObject(Module module, RuntimeMethodHandle ctor, IntPtr& blob, IntPtr blobEnd, Int32& namedArgs) at System.Reflection.CustomAttribute.GetCustomAttributes(Module decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType, Boolean mustBeInheritable, IList derivedAttributes) at System.Reflection.CustomAttribute.GetCustomAttributes(Assembly assembly, RuntimeType caType) at System.Reflection.Assembly.GetCustomAttributes(Boolean inherit) at C1.Web.Util.a.a(Assembly A_0, String A_1) at C1.Web.Util.a.a(String A_0, Type& A_1) at C1.Web.Util.a.a(Type A_0, ClientScriptManager A_1, String A_2) at C1.Web.C1CallbackHelper.c.b() at C1.Web.C1CallbackHelper.c.a(Object A_0, EventArgs A_1) at System.Web.UI.Control.OnPreRender(EventArgs e) at System.Web.UI.WebControls.BaseDataBoundControl.OnPreRender(EventArgs e) at C1.Web.C1WebChartBase.baseWebChart.OnPreRender(EventArgs e) at C1.Web.C1WebChart.C1WebChart.OnPreRender(EventArgs e) at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---
Source:
Server Name: T60P

Have you tried using 4.6.2?

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-Mitchel Sellers
Microsoft MVP, ASPInsider, DNN MVP
CEO/Director of Development - IowaComputerGurus Inc.


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Well I spoke to soon. When I converted my project the configured chart was not working. Plus a couple of other seemingly unrelated issues.

In fact, when I went back to the empty test project, its chart was broken again also. But, at least I figured out how to reproduce it:

Using starter kit, make a new 4.6.2 web site.Create a module using the starter kit. In the View control for the module, delete the datalist and its event code. Drop a C1WebChart on the empty control. Run the project. Use Import Module to install the module, change cache to 0. Drop it on a page. Looks fine. No error, chart displays.

Go to Module Definitions. Go to the bottom and check all the stock modules to be installed. Install them. Fine. No errors.Exit.

Start again and the build will fail. It is looking for Dotnetnuke.modules.gallery. 3.0.11. Find and move a copy in to the bin directory. (Actually I had 3.0.12, don't know yet if that is part of the issue). Start the project again and it will start up fine now. Go to the page with the chart and it has the tag prefix error again.

I intend to troubleshoot some more, maybe 1 stock module at a time to see if there is just one culprit. But I need to recover my site back to 4.5.5. first.