I need help, I try to run a GMM estimation method in R but it gives me the error message,

Error in solve.default(crossprod(WX, t(crossprod(WX, A2)))) : 
  system is computationally singular: reciprocal condition number = 3.59161e-23

Which I don't understand.

I'm using a dynamic panel model (Consumption is the dependent variable and lag consumption is also included as an independent variable. to study the effect of GDP on consumption.