ETABS Cnstr Warning??

[mrfbsns]

Hi all,

I am getting warnings in ETABS saying

NUMERICAL PROBLEMS ENCOUNTERED DURING EQUATION ASSEMBLY

TYPE LABEL DOF X_COORD Y_COORD Z_COORD PROBLEM VALUE
Cnstr 10 U1 19190 6150 0 Diag = 0 --> 1.00E-10
Cnstr 10 U2 19190 6150 0 Diag = 0 --> 1.00E-10

I have no idea on what "Cnstr" type is actually referring to, and how to fix it.
Can someone shed a light on this problem? It will be greatly appreciated.

Thank you very much.