Hi,
when copy-pasting blocks from one Rhino instance to another through clipboard, the BlockManager gives an error on missing geometry.
Version 6 SR31 (6.31.20315.17001, 11/10/2020)
VisualARQ 2.9.1.14486 (2020/11/04)
Edit: Behaviour seems to be linked to VisualARQ plugin. Works, when VisualARQ is not active.