Why won't SolidEdge (ST4) let me thread a cylinder???

Sometimes when placing a thread on a cylinder Solid Edge (ST4) gives me the following error. . .even if I already have the cylinder set at the correct OD for the thread I am trying to create. ".XXX-XX thread cannot be placed because the selected cylinder cannot be update to match the selected thread diameter." I have even double checked the HOLES.txt file to make sure the diameters match. Frustrating to have such a simple task work sometimes, but not others. Thanks for the help!

Re: Why won't SolidEdge (ST4) let me thread a cylinder???

Never mind; I figured it out. . . . . .the diameter dimension of the cylinder was locked; unlocking the dimension allowed me to place the thread on the cylinder. Apparently the thread tool needs to adjust the cylinder dimension regardless of whether the cylinder is already the correct diameter or not. . .