I just installed a trial version of Autocad 2016 LT. When I open a drawing saved as Autocad R14 or Autocad 2011, I get a weird pattern of lines on my screen, looking like a spider web. I cannot select these lines to find out what they are. It looks as if it has to do with dimensions and leaders, but not all of them. One or 2 lines coming from the 0,0 coörd.The pattern shows in model space as well as in the lay-out.Any one who has a clue?

Attach a copy of the drawing to your next post and I'll open it up on my computer using AutoCAD 2016 to see if the same thing happens.Personally, I don't think it has anything to do with the version of AutoCAD that the drawing was saved in because I open drawings from many versions of AutoCAD dating as far back as 1985 and have no problems that sound like what you described.Any problems creating a new drawing with LT 2016?

My guess it you have graphic adapter issue, check this solution on Autodesk Knowledge Network: Unwanted linework appears when opening drawings in AutoCAD 2015/2016

Thanks John Connor and Edwin. Yes, it was a video card / graphics issue and the solution is to be found in the Autodesk Knowledge base: https://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/Unwanted-linework-appears-when-opening-drawings-in-AutoCAD-2015.htmlFor me the problem is solved. To John: on the page mentioned above you can find an example of the problem described.

Glad to hear you got your problem resolved.