This is a solution for specific (and maybe somewhat obscure, but it helped me, so perhaps it will be helpful to someone else) scenario for Infragistics’ WebHierarchicalDataGrid error “Async request failed“.
It could be accompanied by inner errors
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request
or more generic
Object Reference not set
In this particular scenario WHDG uses manual LoadOnDemand for to populate children (i.e. RowIslandPopulating
event is used) and parent grid is sorted by one or more columns. Error is happening when attempting to expand second child or a grandchild. Continue reading →