[Gretl-users] Error output of the switching algorithm

Dear gretl list, I am trying to estimate a few restricted VECMs, but the estimation does fail quite often using the default switching algorithm. Actually, I just would like to know to what exactly does the following error message refer to: "Switching algorithm: failed Exact or near collinearity encountered" I could not find any hints in the C-sources. Are the restrictions collinear or is it the high correlation between variables? Thanks in advance, Artur