Mariusz Skrzypczyński

Add timeshift node after vellumsolver and set it to whatever frame you want as output or... switch Simulation Type in solver from dynamic to Quasistatic. and if you don't turn off Enable Automatic Resimulation it will update automatically so no need to press Reset Simulation.

unreal_data_table_rowstruct must point to existing structure.
To populate table with data you have to set attribute unreal_data_table_xxx where xxx is variable name set in structure.
unreal_data_table_xxx and xxx variable in structure must be of the same type.
And it's good to define where resulting data table should be stored. For this you should set unreal_object_path attribute.
All these attributes should be point attributes.

Maybe it's because Houdini (not engine) don't know where to look for nested HDAs.
Try adding line in houdini.env :
HDA_LIB = _yourFolderWithNestedHDAs
Hope it helps.