I applied a glue contact between two meshes and it said 'successfully found a pair' However the glue ptach has a red cross and the glue has an exclamation mark in the tree.
Note that you can have an Assembly of Assemblies - so if you put your two current Assemblies inside a third, then the glue should go back to being valid.
Note that you can have an Assembly of Assemblies - so if you put your two current Assemblies inside a third, then the glue should go back to being valid.