I am working with Civil 3D 2018 on a stream project with the River & Flood Analysis Module. After several weeks developing the plans and getting ready to lay out my plan sheets, I noticed that I could not delete any viewports on my layout pages. To make a long story short, I tried to WBLOCK the drawing and start in a new file, but I received a "Error Writing/Closing File" message. I then began trying the Recoverall, Recover, -Purge, Audit, Purge, Overkill process in the hopes of correcting the problem. No luck. I went back to some of my older, recent files to see if there was any problem with the viewports on them. No problems there. I also tried deleting items in my corrupt file one by one to see if I could track down the culprit. I deleted the entire drawing and still could not succeed in deleting viewports created. While old drawings worked fine, when I created a brand new file, I could delete viewports automatically created. However, as soon as I opened the corrupt file, I could no longer delete them. I haven't a clue what this is all about. Anyone?
