Cannot mount DMG file!

[equalme]

Running 10.8.4 on my MBA. Recently unable to mount any DMG files to be installed.

Using DiskImageMounter: Errors saying The following disk images couldn't be opened - Not recognized.

Using DiskUtility: Unable to attach DMG - Not recognized.

Very frustrating that I couldn't figure out the fix even via googling.

Any help please?

Thanks!

 

[Intell]

Have you restarted your machine? Try that and see if it continues to happen. Are these downloaded DMGs?

 

[equalme]

Have you restarted your machine? Try that and see if it continues to happen. Are these downloaded DMGs?

Yes downloaded. But I've tried all sorts of other DMG files and nothing works.

Restarted computer multiple of times. Tried safemode and it still won't mount. Logged into guest account and still no go.