Problem is when you remove sort from all columns. In this case, jqGrid sends sidx as empty. 

I think, it will be more natural to set sidx to sortname and sortorder.

Setting sidx to empty makes server-side to decide default sorting.

And in case of Entity framework, it may end up throwing 'Skip before OrderBy' exception'.

Btw, I gave this bug not so useful topic and I do not know how to edit topic title 🙁