I have Visual Studio 2010 Professional installed as well as ArcGIS 10 SDK for .NET SP2 integrated with the VS2010. I have started looking at add-ins, but run into an error when performing this sequence of steps. 1) Right-click the solution name in the Solution Explorer and choose Add > New Item. 2) In the Installed Templates menu, choose Desktop Add-Ins and then Add-in component. Define the name properly. 3) In the left panel, click on the Add-in Command Bars. The error message "Numeric value is expected. Parameter name: parameter" pop-ups from the Microsoft Visual Studio. The software is hanged now and needs to be restarted in order to be able to work again.
I was not able to find any useful information about this error neither on MSDN (this error is related often to some programming practices like casting integers to strings and vice versa and has nothing to do with ArcGIS Add-ins) or Esri forum (I assume that add-ins are relatively new to the community).
Could you please share some thoughts what could I miss here? Are you able to reproduce the problem?
I've got exactly the same issue. It could come from the decimal separator in the regional settings. For me, the decimal separator was originally a ",". When i replaced it by a ".", everything work well. There's a NIM about this issue: NIM066373. I hope it's help !