file crash after exporting (creates correctly dxf and dwg)

as in the title, file crash after exporting (creates correctly dxf and dwg). It repats ecerytime, please find attached the crash report.

Python backtrace

File "/Users/dr/Library/Application Support/Blender/3.1/scripts/addons/prj/working_scene.py", line 123 in remove File "/Users/dr/Library/Application Support/Blender/3.1/scripts/addons/prj/main.py", line 464 in reset_scene File "/Users/dr/Library/Application Support/Blender/3.1/scripts/addons/prj/init.py", line 72 in reset_scene File "/Users/dr/Library/Application Support/Blender/3.1/scripts/addons/prj/init.py", line 100 in execute File "/Users/dr/Library/Application Support/Blender/3.1/scripts/addons/prj/init.py", line 134 in invoke

[scansioni_con_inserti_semplificati.crash.txt] (/uploads/7f423c308c850cd4814766fbb950853f/scansioni_con_inserti_semplificati.crash.txt)