I'm trying to setup a development machine for upgrading Kentico 11 to 12. Version 11 is under TFS source control and packages are not added to source control.
On dev machine I used NuGet to add Kentico.Libraries and Kentico.Libraries.Web.UI packages.
The solution on dev machine is compiling, but I'm getting this runtime error when I try to browse to Kentico CMS
The file '/CMSModules/Chat/Controls/SupportChatHeader.ascx' does not exist
On
I had this issue a couple of times when upgrading with Kentico hotfixes. In my particular case I did not require the CMS.Chat module so uninstalled it via the Kentico Installation Manager. However, because my CMS project had a reference to the Kentico.Libraries NuGet package, my CMSApp project had assembly references added back to the CMS.Chat.dll assembly - this time referenced from the NuGet package folder.
In this case I simply removed the assembly references to the DLLs I did not need so that they were not copied to the bin folder. I think if the DLL is present in the bin folder then Kentico considers the module to be present and will then try to load the controls, but of course if the Kentico module was uninstalled then so were the ASCX files, which is what causes the exception.
My assumption is that the missing files been removed or were not added to TFS, which would go some way to explain their absence. If you have other functioning environments (UAT or perhaps production), then I would think about copying the files back from them to update the local environment.
I have had a similar issue once before, but we found that the upgrade replaced the missing files for us, so it may be worth just giving the upgrade a shot.