Mostly with TEXT entities, but also with BLOCK.
This offset leads to CRC errors, requiring recovery. 
But with re-encode even to data-loss of subsequent entities: ../to/r9/from_autocad_r10/TABLET.DWG

eg 
TEXT ../to/r11/from_autocad_r12/sample/ADESK_B.DWG
BLOCK  ../to/r11/from_autocad_r11/SAMPLE/TROL1.DWG (offset 10!)
preR13 store ERROR: offset slack in unknown_bits
This is a GitHub Issue
repo:libredwg
owner:LibreDWG
Title : preR13 store ERROR: offset slack in unknown_bits
Issue date:

--- start body ---
Mostly with TEXT entities, but also with BLOCK.
This offset leads to CRC errors, requiring recovery. 
But with re-encode even to data-loss of subsequent entities: ../to/r9/from_autocad_r10/TABLET.DWG

eg 
TEXT ../to/r11/from_autocad_r12/sample/ADESK_B.DWG
BLOCK  ../to/r11/from_autocad_r11/SAMPLE/TROL1.DWG (offset 10!)
--- end body ---
