Kendo Grid "TypeError: u is undefined"

possible reason you may find this nondescript error

TypeError: u is undefined

I was getting this strange error while using KendoGrid which I had used many times before and I couldn't figure out why. I was simply calling:

On a simple table, nothing special. Turns out it was simply because I had used some <th> in the <tbody>, but it can only be located in the <thead>.

KendoUI : TypeError: n.slice is not a function

common error in Kendo UI that has a simple solution

The error:
TypeError: n.slice is not a function

Is not very clear, but it is pretty simple. You are generally using some sort of AutoComplete, DataGrid, etc. This simply means that you are not returning a collection (JSON), but a layer (or more) up from that collection you want to include. For example, you would be returning this JSON:

When what Kendo is expecting is just this: