Bad update messages:

• generally a corrupt frame found in the file.
• If the file finishes encoding, it should be okay. It will skip the suspect frame(s).

ERROR: Invalid input File
That is a peculiar problem that pops up occasionally. A few things to try:

• Ensure that the file is not 'in use' by another program such as a media player. (close other apps or even restart your system) That is the most common problem.
• Check the full path(s) for spaces, non-standard characters, etc.
• Be sure that the file is not in an uncommon format. Even though the extension is .avi, it could be unreadable in many programs
• Videos encoded from CD --if the source file is on a disk that you cannot write to, be sure to specify an output path!