I getting exception for Expand child grid, When i add client template ProductId / ProductName exception.
columns.Bound(m => m.ProductId)
.ClientTemplate("<a data-id='#=ProductId#'>#= ProductName #</a>");
Below code value is undefined,
columns.Bound(m => m.ProductId)
.ClientTemplate("<a data-id='#=data.ProductId#'>#= data.ProductName #</a>");
After continues effect, we found that it is retuning parent data item row.
Fix is to escape # by \\# in ClientTemplate.
columns.Bound(m => m.ProductId)
.ClientTemplate("<a data-id='\\#=ProductId\\#'>\\#= ProductName \\#</a>");
// OR
columns.Bound(m => m.ProductId)
.ClientTemplate("<a data-id='\\#=data.ProductId\\#'>\\#= data.ProductName \\#</a>");