Which version Aspose.Grid.Web you are using, did you try the latest 1.9.4. And kindly make sure that you have installed Aspose.Grid.Web properly, you may try to uninstall and then install it as fresh to check if it works fine.
If you still find the issue, kindly give us more details where you got these error messages and tell us about your env., os, .NET framework, IIS, Browser type etc. You can create a sample test project with all the source files, zip it and post it here, we will check it soon.
Those exceptions are normal. The grid uses some special technologies to get the client side resouces. Do not worry about them. You may ignore these exceptions. If you just can't ignore these exceptions for some reasons, you may do following this:
add this config section to the web.config:
This config prevent the control from using embeded client resource(images, scripts, etc.). And this config will only take effect with LICENSED controls.