If a file cannot be opened, take the following steps. But you need to know that this method probably may not to work on Macs. But I would suggest you to try...

• RECOVER command 
  --Recovers a selected drawing file 
  --If successful, open and run AUDIT command 
  --Evaluates drawing integrity and possibly more error correction 
  --Set system variable AUDITCTL=1 to create a report of audit results

• RECOVERALL command (introduced in AutoCAD 2008) 
  --Recovers a selected drawing file 
  --Attached and nested xrefs are also opened, repaired, resaved, and closed
• INSERT and EXPLODE
• Start a new DWG with no template 
  --Run INSERT and selected the corrupted drawing 
  --Check the “Explode” option

Reserve way might be following helpful and effective articles, tips, trick and etc. solutions in the following...

https://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/AutoCA...

https://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/Drawin...

https://onlinefile.repair/en/autocad.html