I understand that you're suggesting plausables. Which is why I addressed it as an unlikely possibility at the end of my last post. I've been pretty detailed on what the issue is, so your unsurity is illogical to me at this point. to reiterate: the web reference isn't generating ClientBase. Thus, what's in the GAC (in a test and deployment scenerio) becomes irrelavant, because it will fail to build.
"Examining the exception's description, I can see that the issue is related to a missing assembly.".. the issue is related to a missing class in the project. if it were a missing assembly our assembly, it would state: "The type or namespace name 'BaseClient' could not be found".. Since there is no BasicClient being generated, there is no snippet that inherits BaseClient in the scope of this issue..
the assemblies: System.ServiceModel (as well as System.ServiceModel.Web) exist in both the project reference dependencies and in the GAC. Furthermore, I can inherit from the ClientBase<T> on a new class in this project and in my own.
I downloaded the most recent Telerik Ajax UI Source (2015_1_401_Source ~ zip), this issue (as expected) persists. The previous version I was using (2014_2_724_Source ~ zip).
With the latest version (and possible the previous one I used) I had to resolve a dependency assembly reference to AWSSDK. Which I did by selecting the reference item, and changing 'Specific Version' in the Properties window ('Reference Properties') to true - it was initially set to false. This, seemingly, satisfied the strong name, specific version dependent assembly that the solution requires..
I don't know what source code you're compiling or where you're getting it, but the source code (download resource) being provided is not buildable without these modifications/configurations/settings..
Please see the attached image (screenshot) of the failed build and web referenced (opened treenode in solution explorer). This screenshot was take after I set the specific version property of the AWSSDK to true, right clicked on 'com.hisoftware.api2' and selected 'Update Web Reference'.