Sometimes when you want to open or save using Autocad products, the dialog box doesn't appear instead the option is shown on the command line.
1. Now the dialog box will appear as usual.
Addition Info (For those who like to know the reason for this to happen):
Some of the LISP or script programming command often disable/ turn off some of the variable settings when executing and restore the original value after finish executing the command. When the command is stop/ interrupted in the middle of execution, the original value is not being restore hence causing the problem.