In a drawing，I want to modify a tolerance of dimension，the dimension was selected in a dimension style。
The first attempt failed, the second was successful。Must modify the tolerance again，then the tolerance is new。
How can successfully modify tolerance at fist time。
May be there is a bug in solidworks。
I find a quickly way to change the tolerance。
first modify the style of dimension to none，then modify the tolerance was successful。
I don't know why direct modify the tolerances was failed。