By Dennis Collin
Recently I had a question from an AutoCAD customer about a problem on a layout sheet with several viewports, where only a few of the viewports displayed model space contents the remaining viewports showed as empty.
This can happen when a sheet has perhaps several viewports on a sheet. AutoCAD in theory can have up to 64 viewports on a sheet, but it is difficult to fit that much information on a typical title sheet! Nevertheless, in certain situations issues can arise when there are as many as several viewports on a sheet, with some viewports not displaying the expected contents.
This problem can be solved by setting the AutoCAD system variable MAXACTVP. A typical setting is 64 (no. of viewports) but it can vary by drawing file and for files created in older versions of AutoCAD or where some AutoLISP code has been run, can set this value to a lower number. To set the variable back to its default value, type in MAXACTVP and enter the default value of 64. This should activate all the viewports and the contents should display as expected.