I am modelling a composite steel beam where in the steel beam and FRP both are modelled as a shell (S4R) and the adhesive is modelled as a cohesive solid (COH3D8). Adhesive is the slave surface and steel and FRP are the master surfaces in the Tie constraint. The beam is subjected to buckling analysis prior to a general non-linear static step. However, for some reasons unknown to me, warnings of numerical singularity pop up as " Solver problem. Numerical singularity when processing node Left Adhesive.559 D.O.F. 3 ratio = 19.5878E+15 .". The analysis aborts with error message The eigenvalues cannot be found. This could be caused due to instabilities in the base state (check for negative eigenvalues in the general analysis step) Where am I going wrong?