Problem

Trying to change the scale of my active linestyle. When I type in the
key-in box, "Change Linestyle Scale 0", and then click on the particular
lines they don't change. Then type in the key-in box, "Active Linestyle
Scale", to see if it has changed to "0" and it hasn't.

Product: MicroStation
Version: Varies
Area: Custom Linestyles, Scale

Solution

You will need to set the scale factor to 1. You can not set it to 0.
Setting the linestyle scale to one is the same as setting it to 0.

You are also using two different key-ins. "Change linestyle scale" will
only do "one" linestyle at a time (this is not global). "Active
linestyle scale" is global and will scale the entire file. So if you
used "Change linestyle scale" this will "not" set the entire dgn file
linestyles scale to 1, it will only do the linestyle that you selected
to change.