Think the autoexec/config.sys probem was the only thing for me.
If it doesn't work in the cvs for you as well/with the normal core
post on the beta board.

Confirmed, posting there.

I bought the game not long after it came out, so I'm pretty sure my discs are the "original" version from 1993 (although the disc printing says 1992 copyright). I don't have any issues installing or playing the game. I used a default .conf file in DOSBox 0.72, but with 10000 cycles instead 3000 for proper speed. There definitely is more than one version of the game, with a later version experiencing an installation problem related to an IOCTL function: Boot DOS and read CD?

Before going on to look at other things, it might be a good idea to take the error message at face value: one of the movie files may be corrupt. Here is a directory listing of the T7G directory on my disc number 1 containing the movie files, to which I added MD5 hashes for comparison.

1Directory of D:\T7G\.
2.              <DIR>            30-03-1993 23:42
3..             <DIR>            31-03-1993  7:42
4B        GJD         25,672,908 08-03-1993 16:00 DA9E17605E5BEB385BC7F573F5E2E53D
5CH       GJD         16,889,832 08-03-1993 15:51 9BCDDB8E2ACB2319584CD9F311342A9B
6D        GJD         31,565,570 08-03-1993 16:14 E8115DCDF7F2F4778042B58F23018511
7DR       GJD         23,532,001 08-03-1993 16:11 065D9F59999343ACEEB30B664BE883DF
8FH       GJD         94,315,192 08-03-1993 16:45 2B3AD973E34CD239DFDE309F0C08F847
9GA       GJD         26,905,546 08-03-1993 16:23 FB4579F2DF810223F095F2A0F4769CF9
10GAMWAV   GJD         10,709,519 16-02-1993 16:49 BAB510145B2FF21F92511DDFB3D9E95F
11HTBD     GJD         43,211,514 08-03-1993 16:37 3B6E97B627840966ED9E1D2154DA1EDE
12INTRO    GJD         30,611,047 24-03-1993 18:55 6E206A6729F63D1E115356A3A6A51618
13JHEK     GJD         45,053,968 08-03-1993 17:03 57EB8238A21ECCE022BF4E8F77015296
14K        GJD         41,165,447 08-03-1993 17:06 2CCC281078FDC95905700C1B7310AE2A
15LA       GJD         31,590,902 08-03-1993 17:13 BA35BBF44931282118BD2A60B4AA1344
16LI       GJD         51,284,217 24-03-1993 14:52 BFEB51C7CB9931022106DDE73CE0CFD4
17MB       GJD         28,133,514 10-03-1993 11:41 A2857BA5E7E2E1B0BBE8A2CC1861597A
18MC       GJD         38,925,255 08-03-1993 17:36 F148C137F93BF196CCE3E2F3FCB97695
19MU       GJD         16,087,706 08-03-1993 17:30 DDE296B65A6599D7FBA1A43688B70ADC
20N        GJD         45,452,282 08-03-1993 17:45 76A141F08B2DD5AAB3C42C566FB62848
21P        GJD         11,897,552 08-03-1993 17:41 4A7372BF105AE2D3542C529931871383
22   18 File(s)       613,003,972 Bytes.
23    2 Dir(s)                  0 Bytes free.

For what it's worth, my copy matches those MD5 hashes.

I, too had this problem when trying to get the game running from image files in DosBox. I tried everything I could and scoured the whole internet just to try to solve this one "not a VDX" file issue.

In the end, I found out that there is a windows player called "WinT7G" that plays the game fairly well. I still have occasional game crashes with some goofy error message, but the point is: if I save often, the game is totally playable this way 😁

I am running Windows Vista Premium Edition SP1 with 4GB RAM, 2.4 Ghz Intel Quad-Core processor, and an ATI Radeon HD 4870x2 vid card. I also got the game to run under XP SP3 on my laptop with a 1.4 Celeron proc and 512MB of RAM. However, my DosBox attempts never make it through the installer - so the windows-based player is the way to go for sure!

The installer can hang at the end of the installation due to poor programming that relies on the existence of AUTOEXEC.BAT and CONFIG.SYS files (which DOSBox doesn't ordinarily need), however the installation is quite useable if you just restart DOSBox.

The "File is not a VDX file" error has been found to be caused by an incomplete disc image (or discs burned from said images) that do not include the correct audio tracks. For example, making an ISO image instead of BIN/CUE could lead to the problem.

The game runs fairly well in DOSBox, so I don't necessarily see a Windows-based alternative as "the way to go"; particularly if you want the game to look and sound as it originally did back in the day.