When evaluating and applying constraints from a User Constraints Format (UCF) file, if a component set is invalid, the entire constraint is ignored or invalidated even though there are other valid components set in the constraint.
For example, the following constraint is entered in "my_top.ucf":
MEGRP EVERYTHING = FFS LATCHES PADS BRAMS MULTS;
The Time Group "EVERYTHING" is not created because BRAMS is an invalid keyword.
If the design is run through ISE implementation tools, the NGDBuild report (*.bld) will contain a warning similar to the following:
WARNING:ConstraintSystem:56 - Constraint <TIMEGRP EVERYTHING = FFS LATCHES PADS
BRAMS MULTS;> [my_top.ucf(1)]: Unable to find an active 'TNM' or 'TimeGrp' constraint named 'BRAMS'."