Unable to evaluate an expression

Excuse me, I am getting an error as

Attempt to evaluate real square root of negative number.
Function: sqrt
Failed to evaluate expression.
Expression: nojac(min(1,(sqrt((comp1.fsi.h2GNS*((comp1.fsi.rho^2)*(((comp1.u fluid-d(r,TIME))^2)+((comp1.w fluid-d(z,TIME))^2)))))/(comp1.fsi.mu*24))))
Failed to evaluate variable.
Variable: comp1.fsi.xi m, Defined as: nojac(min(1,(sqrt((comp1.fsi.h2GNS*((comp1.fsi.rho^2)*(((comp1.u fluid-d(r,TIME))^2)+((comp1.w fluid-d(z,TIME))^2)))))/(comp1.fsi.mu*24))))
Failed to evaluate variable.
Variable: comp1.fsi.vhNS lin, Defined as: ((0.5*sqrt((max((comp1.fsi.tau m*(((comp1.fsi.res u*comp1.fsi.xi m)^2)+((comp1.fsi.res v*comp1.fsi.xi m)^2))),0)*comp1.fsi.B0YigijtauNorm2)))/(comp1.fsi.B0YigijtauNorm2+eps))
Failed to evaluate expression.
Expression: nojac(((1.4142135623730951^(1-shapeorder(comp1.u fluid)))*max((comp1.fsi.vhNS lin-comp1.fsi.vhNS quad),0)))
Failed to evaluate variable.
Variable: comp1.fsi.vhNS, Defined as: nojac(((1.4142135623730951^(1-shapeorder(comp1.u fluid)))*max((comp1.fsi.vhNS lin-comp1.fsi.vhNS quad),0)))
Failed to evaluate temporary symbolic derivative variable.
Variable: comp1.fsi.crosswindnsVDN${test8}, Defined as: ((comp1.fsi.rho*comp1.fsi.vhNS)*((comp1.u fluidr*(-comp1.fsi.gijrr))-(comp1.u fluidz*comp1.fsi.gijrz)))
Failed to evaluate expression.
Expression: d((2*comp1.fsi.crosswindns*pi*r)*(dvol spatial),{test8})
Last time step is not converged.

Can Any one answer this pls