See and test sample drawing from Wang

Scenario 1 – Using 2018 Version to open
Opening an AutoCAD 2013/LT 2013 format file.
Regenerating model.
This drawing was last saved with an earlier version of the software.
Saving the drawing will update any AEC objects in it to the current version, which will be incompatible with earlier versions.
If you are using this drawing as an underlay you should complete your work in a separate drawing and externally reference this one.
Press ENTER to continue: Drawing cannot locate the project (08_References-6D208D2D-D6DF-4025-
8DB6-8815A975AE47)
Findings
1) Open just fine copy paste any objects no issue, even blocks copy paste and subassembly
2) Command: AUDIT
Fix any errors detected? [Yes/No] N : y
Auditing Header
Auditing Tables
Auditing Entities Pass 1
Pass 1 9300 objects audited
Auditing Entities Pass 2
Pass 2 9300 objects audited
Auditing Blocks
124 Blocks audited
Auditing AcDsRecords
Total errors found 0 fixed 0
Erased 0 objects
3) Something built in 2018 fix the issue just by opening the file

Scenario 2 – Using 2016 Version to open
Opening an AutoCAD 2013 format file.
Regenerating model.
Press ENTER to continue: Drawing cannot locate the project (08_References-6D208D2D-D6DF-4025-
8DB6-8815A975AE47)
Findings
1) Command: AUDIT
Fix any errors detected? [Yes/No] N : y
Auditing Header
Auditing Tables
Auditing Entities Pass 1
Pass 1 9300 objects audited
Auditing Entities Pass 2
Pass 2 9300 objects audited
Auditing Blocks
124 Blocks audited
Auditing AcDsRecords
Total errors found 0 fixed 0
Erased 0 objects
Command: AUDIT
Fix any errors detected? [Yes/No] N : *Cancel*
Command: *Cancel*
Command: *Cancel*
Command: AUDIT
Fix any errors detected? [Yes/No] N : y
Auditing Header
Auditing Tables
Auditing Entities Pass 1

Pass 1 9300 objects audited
Auditing Entities Pass 2
Pass 2 9300 objects audited
Auditing Blocks
124 Blocks audited
Auditing AcDsRecords
Total errors found 0 fixed 0
Erased 0 objects
2) Draw polyline, select then CTRL+C
3) Test again with -pu re * n (Still same as # 2 Fatal Error)
4) Open again with 2016
(Still same as # 2 Fatal Error)
5) Try AutoCAD Civil 3D BatchSave

(Still same as # 2 Fatal Error)
6) Ok, I tried to open this using 2018 and no issue at all
7) Save as 2013 version and open again in Civil 3D 2016
8) CTRL+C
Tadah!! Not much help. maybe just upgrade to 2018. 2016 = Fatal Error Additional Info:
I have 1 Civil 3D drawing done in Civil 3D 2016 and sometime in April 2018 it suddenly crashes every time I copy (CTRL+C) a subassembly It crashes instantly. I save as the drawing deleted everything and purge all and purge regapps and audit and clean the whole drawing leaving nothing. I created new assembly paste any ootb subassembly and try to copy (CTRL+C) and it still crashes and do fatal error. Tried to run Civil 3D Batch Save Util for 2016 and still didn’t fix the issue. The only way I fix that drawing and do copy and paste is to use Civil 3D 2018 onwards.
Findings
I think using Civil 3D 2018 will simply fix them. I don’t know why but it works. If you can get beta or any higher version of Civil 3D 2018 onwards then it’s worth checking any corrupt file and see if using higher version will fix the issue.