Solve an equation containing normcdf

Hi

I am trying to solve for m in this equation

syms m solve ((sigma * exp(-(r + (sigma^2)/2) * tenor - sigma * (sqrt(tenor)) * m) ... * normcdf(-m)) - (r * erf(sqrt(( 0.5 * ((3*sigma / 4 - r/(2*sigma) ... + m/(2*sqrt(tenor)))^2) + r) * tenor)))... / (sqrt(( (3*sigma / 4 - r/(2*sigma) + m/(2*sqrt(tenor))^2) + 2 * r))))

but there is an error in: normcdf(-m) and I dont know why

they put: Error in normcdf (line 60) p = NaN(size(z),class(z));

I didnt understand how can I fix the error.

If anyone can help me I ll appreciate it

Thank you