Got Same problem… did you find any alternative to this ?
I was able to fix this issue by taking the latest GridSearch from https://github.com/tieniber/GridSearch/raw/master/dist/GridSearch.mpk
and replace widget with your current one and it looks different than old widget.
Hope it resolves this error,
Instead of DataGrid, Try DataGrid 2 and add a Custom Search
Or you can try to Create a custom search filter using non-persistent entity: