I get this error when I copy items from a block, close the block and paste the items (outside the block). No problem to go on working.
1 block instance added to selection.
Block Editing part “ANBa”
2 curves, 4 polysurfaces added to selection.
Command: '_CopyToClipboard
Creating meshes… Press Esc to cancel
Command: '_Paste
Error reading BlockEdit plug-in data