[gmx-users] g_wham error

[asasa qsqs]

Dear Justin,I want to calculated the PMF for passing a drug from Z-coordination of DPPc bilayer, at the end of calculations i gave a fatal error as following:Fatal error:
 Found pull geometry 'position' and more than 1 pull dimension (3).
 Hence, the pull potential does not correspond to a one-dimensional umbrella
 potential.what must i do exactly? I want to give PMF along the Z axis.many thanks,Mahdavi