Where is the file you are trying to open? Is it on the desktop/computer or an external HD? Are you sure it is in fact an .indd file? Could someone have just renamed the file with the indd extension?
In the desktop... but I solved! Just open as copy, not as normal like usually, now I am saving like .idml, open again the new Untitled... renamed and Done!
But thank you anyway!
Things what I done before:
Restart the computer, restart the preferences of the application