Sometimes it can happen, that when opening a file, it seems that AutoCAD has gone crazy and the command bar says:
Enter name of drawing to open <C: \ Program Files ...
The problem: it does not show us the browser dialog when using the commands to open or save files. It is because the dialog variable is disabled.
It is solved with the command FILEDIA.
Eye!, It's not FIDELIA, like the name of the grandmother of Gijón, but FILEDIA of File Dialog.
We write FILEDIA, then Enter, we write the variable 1. And ready.
Something similar can happen with the commands, and is solved in the same way with the variable CMDDIA.