Unable to scan, archive is password protected ?

[wile_e]

I did a virus scan yesterday, and the log came up with that error. The ZIP files it was trying to scan are NOT password protected. Why can't Avast read the ZIP file? Maybe the ZIP is using a new compression method? Unfortunately, I closed the dialog box to the error message. Now I can't find these errors in the logs. Where does Avast keep the log for the last scan?

[essexboy]

Right click the spinning blue ball and select Avast log viewer   The fact that the zip files cannot be scanned may be because it is not a recognized packer, however feel safe if it is unpacked and contains a gremlin standard shield will find it.

[igor]

If it were an unknown compression method, avast! probably wouldn't announce the archives as password-protected (but rather as corrupted, or maybe even "unknown compression").
How do you know the files are not password protected? Where do they come from? (what is their location/origin?)