ArcGIS 10.1 crashing on using Flow Accumulation tool

[AjayMore]

Hello all,
I am trying to make a flow accumulation grid using Arc Hydro and it keeps on crashing, although its a big file its not huge.
Any ideas how can I stop Arc GIS 10.2 from crashing.

PS: It has started to happen much more frequently after university upgraded from ArcGIS 10 to ArcGIS 10.1

Thanks

Ajay

[ChristineDartiguenave]

Did you reinstall Arc Hydro after the upgrade?

Christine Dartiguenave
Esri Water Resources Team