I am giving Vegas Pro 13 a try as a possible alternate to my existing NLE.

Trying to import the most ancient file known to a Windows computer (OK, one of the oldest files) and I can't believe my eyes... Vegas can't work with good old DV AVI files??? What in the world are you thinking Sony? The error message is : "The file is most likely corrupted or of an unknown format". Unknown to who?

The files have been captured from a Sony PD170 via firewire to a Focus FS-H200, then copied from the CF card to the hard drive. They work fine in every player known to man, even primitive Windows Media Player, so it doesn't seem to be a codec issue. They work in every NLE and video processor I have ever tried in my life.

At first I thought I came across a corrupted file, but then I Googled the problem and voila, the interweb is full of good-will advice from installing the worst codec pack ever (K-Lite) to encoding to a "more acceptable" format - give me a break! What can be more acceptable than DV AVI???

Here's the format report from MediaInfo:

Format : AVI
Format/Info : Audio Video Interleave
Commercial name : DVCPRO
File size : 1.86 GiB
Duration : 9mn 13s
Overall bit rate mode : Constant
Overall bit rate : 28.9 Mbps
Recorded date : 2015-12-16 11:31:58.000

Video
ID : 0
Format : DV
Commercial name : DVCPRO
Duration : 9mn 13s
Bit rate mode : Constant
Bit rate : 24.4 Mbps
Encoded bit rate : 28.8 Mbps
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate mode : Constant
Frame rate : 29.970 (29970/1000) fps
Standard : NTSC
Chroma subsampling : 4:1:1
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Bottom Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 2.357
Stream size : 1.85 GiB (100%)
Encoding settings : ae mode=manual / wb mode=one push / white balance= / fcm=manual focus

Audio
ID : 0-0
Format : PCM
Muxing mode : DV
Muxing mode, more info : Muxed in Video #1
Duration : 9mn 13s
Bit rate mode : Constant
Bit rate : 1 536 Kbps
Encoded bit rate : 0 bps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 101 MiB (5%)
Encoded stream size : 0.00 Byte (0%)

Please tell me I'm doing something wrong and Vegas does in fact work with DV AVI...

I'm on a Win7Ultimate/64 PC.

Ervin,
The file is identified as DVCPRO, not "standard" DV. I recall DVCPRO as a Panasonic DV "format" that may not be read properly by Vegas. DVCPRO tapes had a wider (18micron) track pitch than DVCAM (15) or regular DV (10). Seems like the Focus 200 transcoded the DV files to DVCPRO along the way.
In any case, Vehas is not reading the files as standard DV.
Even the DVCPRO HD100 format was not natively recognized by Vegas until later versions of Vegas pro.

Perhaps your best bet would be to render the files to "standard" DV (or an intermediary format like Cineform) in your other NLE and then import into Vegas.
A PIA, I know, but it would likely work for you.
Ken

ken hits the nail upon the head....

vegas works very well with dv - not so with dvpro...