[est1895]

Hello. This is the error message that I get when I try to play chapter 3:

FreeSpace was unable to find 1 ship class while loading this mission.  This can happen if you try to play something that is incompatible with the current mod. The current campaign is 'At All Costs' and the current mod is IDOH 1-4(Itdoh Chap 3 IDTOH2')  You can continue to load this mission but it is quite likely that you will encounter a large no# of mysterious errors.  It is recommended that you select a campaign that is compatible with your current mod or else exit FreeSpace and select a different mod.

Now I got these campaigns in the SCP files of www.freespacemods.com I am also using the MediaVP 3.6.10 beta and launcher 5.5d with SCP 3.6.9 

Any help would be appreciated

[blowfish]

I think that selecting 1-4 would produce weird results.  For chapter 3, IIRC you need ch.2 as well, so just select 2 and 3.  And make sure that the chapter 2 campaign is visible in the campaign room (multiple mods tends not to work for me).

[WetNavySailor]

This is an easy fix. ITDOH chapter 3 uses files out of the chapter 2 VP, so you need to change your mod.ini file for chapter 3 using Notepad (or any other suitable text editor) so that chapter 3 will access the chapter 2 VP files. Open the mod.ini file for chapter 3 and look for the following line:

[multimod]
secondarylist = MediaVPs;

and change it to this:

[multimod]
secondarylist = ITDoH2,MediaVPs;

If "ITDoH2" isn't the name of your chapter 2 mod folder, just replace it with the correct one.)

That should take care of the problem.

[blowfish]

IIRC Chapters 4 and 5 are standalone.

[WetNavySailor]

I realized that: I was editing out all chapter 5 references when you posted your reply.

[blowfish]

If mod.ini doesn't work for you (which it doesn't for me), just copy the ch2 VP into the ch3 folder.