It sounds like you have stumbled upon one of the most important "hidden" tools in AutoCAD, particularly if you work in Civil 3D or Land Desktop.
EXPLODE command on complex AEC objects (use EXPLODE sparingly; use AECOBJEXPLODE for better results).BURST on blocks containing SHX attributes to convert them to standard text.A frequent headache for CAD users is receiving a "Missing SHX Files" error when opening a drawing. This happens when a drawing uses a linetype or text style dependent on aeccland.shx , but the file is not in the program's search path. aeccland.shx
Use the PURGE command or specialized tools like Batch Save Utility to strip out legacy DGN linetypes and shapes if they aren't actually needed in your project. It sounds like you have stumbled upon one
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