DivX is a delivery-only format/CODEC. PrPro cannot work with it. Having the CODEC installed on the system, is only for playback.
The best course of action is to convert this footage to something that PrPro can work with. If SD material, choose DV-AVI Type II. If silent, then just use the elemental/elementary video-only stream.
It is very likely that even though the Clip is silent, the DivX CODEC is being misread, or maybe there is a silent Audio stream inside the container, and it is set to something that PrPro cannot handle.
Conversion will allow you to get the file into PrPro, but it will NOT fix the very heavy compression of the DivX CODEC, so quality will NEVER be recovered.
PS - I use DigitalMedia Converter for such, but there are plenty of free converters out there. I do not know which will work with DivX.
From Harm Millaard in another thread:
You can use DV AVI type2 without problems, you can't use DivX, Xvid and all those other crappy delivery formats, even if they are wrapped in an AVI container.
AVI is just a container. What is relevant is the contents of the container. It can contain scrap metal, chemicals, food, electronics, old shoes, furniture, personal care stuff, and what have you. Same for Premiere Pro, the AVI can contain all sorts of stuff, but the only thing that PR really likes to edit inside an AVI container is DV AVI type2. If it is anything else, either don't edit it, or convert it to an editable format, or use other software. Use Gspot to figure out what is inside, but if you were right to start with and it is indeed DivX, those three approaches are all the options.
Thanks Jeff. Harm said it much better than I could have.
I wasn't trying to put forth a "better" response; all I wanted to do was
consolidate both topics into one without omitting any relevant info. I
think both answers are good, and both deserve to be included.