When I install 11.07 on my machine, o2c doesn't worked properly anymore and Dcad11 crashes all the time. What to do 
Hello Rudy,
I've noted that the newer version of o2c Object Viewer is not completely compatible with DataCAD 11.07, and additionally it don't allow some adjustements we can do in today's engine.
My first suggestion to you is to install back the old one and check its behavior.
If you don't have it available, download a copy from here:
https://www.datacad.com.br/down/sup-dc/o2csetup.exe
Regards,
Miguel
