"Locked Layer" Error Message

When I try to open an AutoCAD drawing or run a Design Master HVAC command, I get an error message saying, "Design Master attempted to modify an object that is on a locked layer. Unlock any layers used by Design Master."

Cause

Typically, if Design Master HVAC inserts or modifies an entity on the drawing that is on a frozen or locked layer, it will automatically thaw or unlock the layer. This error message appears in situations where the software is unable to unlock the layer.

Solution

If you are able, run the AutoCAD LAYER command in the affected drawing and unlock any layers that Design Master HVAC may use. Default Design Master HVAC layers begin with DM-, M-, ME-, or MN-. If you aren't sure whether Design Master HVAC is using a particular layer, unlock it.

If the error message pops up repeatedly when you open the drawing and you cannot run the LAYER command, you may need to open the drawing in an AutoCAD version that does not have Design Master HVAC loaded to unlock the layers, or have another person open the drawing and unlock the layers for you.