_executetool Duplicate definition of block XXXX ignored.

My tool palette stops working after I drop one block. _executetool Duplicate definition of block XXXX ignored. This only happens in this drawing. If I open a new drawing I can drag and
drop all day. Is there a setting that I need to adjust? The INSERT command works every time BTW...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.