Hey all,I trying to make a block which has two visibility states, one with a attribute definition and the second visibility state without the attdef. If anyone has successfully produced a block that meets this operations your advice is greatly appreciated. Thanks

Sounds simple enough.  Either the attribute is showing (ON) or it isn't showing (OFF).  It would be treated like any other part of the block.

Here is a simple block called AttributeVis with some test text that can be turned on or off.  Saved in 2010 file format.uploads/165260/AttribVis.dwg

Thank you very much :)