Hi I have also noticed a bit of a glitch, but it is in the unfinished .4 version. I have tried two easy Borg campaigns just to check things out. Both times about 70 turns in, one of the unknown player's turns never ends.

I was unable to progress past it by going to an old save, but I had been saving every two turns. I will set it to every turn and try again. Thanks for the advice.

Most likely, remove the Dreadlord campaing trigger xml fromt he game folder and play a game, see if it CTD's. The assaultfighter is not new it appeared in 1.8 and I have no clue why it is there or see hwo to fix it. Tellarite ship I will fix when I get around to redoing all the designs so they do not cross over liek they do now(i think 5 of my sets use terran as default, i am planing to assign 1 ST faction to 1 Vanilla shipstyle).

So I followed the installation Instructions exactly. I get the new splash screen then crash. This is on a clean install with all but the newest DLC: Altarian Prophecy DLC, and the sound track.

I have some ship's from the Steam workshop installed as well but other than that it's just your mod. Any clue as to what the trouble may be? 

Have the debug.err if you want to look at it.

Just realized I had not installed the ST Colors. going to wipe and reinstall everything in order again and see if it works this time. And will back up All the original files  so I don't have to DL again.

Installation instructions mention a ST Core mod

Depedancies:

Star Trek - Colors is required.
Star Trek - Core is required. (Depends on Star Trek - Colors)

Is this your mod or is there a link for it?

If you have Aidens pallets or Star Trek - Colors off the nexus installed, which it looks like you do, due to the duplicate entries, you need to uninstall it/them. It has been integrated into GST.

These mods have been combined and is no longer relevant.

Installation

ALWAYS Remove any Previous Versions of this mod, ALL folders, as I regulary have a Folder restructure and edited some filenames to be more inline with the rest of the mod.
If you do not remove the old version you will have duplicate entry errors.

Make a back up of GradientMap.png & GradientMapLights.png located in ...Steam/steamapps/common/Galactic Civilizations 3/Gfx

Place the two folders located in: [For You Game Directory] here:-

...Steam/steamapps/common/Galactic Civilizations 3 (Or where ever you installed the game)
Overwrite when prompted.

Place the two folders located in: [For your My Games - GalCiv3 Directory] here:-

...Documents/My Games/GalCiv3
Overwrite when Prompted.

GST Alpha 0.3h Patch 1.2

Extract to:- ...My Games/GalCiv3/Mods/Star Trek - Core
Overwrite when prompted.

1.82 Text String Overflow Fix

Extract to:- ...My Games/GalCiv3/Mods

Optional:-

Place the three folders located in: [Cosmetic - For You Game Directory] here:-

...Steam/steamapps/common/Galactic Civilizations 3 (Or where ever your installed the game)
Overwrite when prompted.

My bad tbh, I have not updated the Readme.txt.

After installation you should see 6 Mod folders in; ...My Games/GalCiv3/Mods:-

1. Colonization Events
2. Enhanced Planet Diversity
3. Star Trek - Core
4. Star Trek - Map Changes
5. Star Trek - Star Names
6. 1.82 Text String Overflow Fix

You have the right DLC's? Mecenaries and Precusor worlds are required.

AnomolyDefs.xml in Map Changes mod. You will see the code commented out (Encounter).

Hey - I am seeing CTD as well from using the 0.4 Alpha Update - will go back to 0.3h see if that fixes the problem - I am hanging up (like stuck turn when processing the other players or complete crash about 65 turns into the game).  I did keep one of my crashes and the debug.err error file.  I have now removed my old workshop fractions and designs since they were mentioned in the Debug file and may not be current with version 1.82 of the game.

Got me curious with all the revisions to Alpha 0.3h of the mod to redo the various mod piece downloads and search through the Debug file looking for problems - never knew there was a C:\Programdata\ file for GC3 - I deleted it in case of corruption from rebooting (fractured space early access caused me to reboot a few times already)

Debug Message:  CTextRenderer::LoadFontData FAILED to load file: C:\ProgramData\Stardock\Galactic Civilizations III\K2FontData_Normal.fontdata.  Data checksum in file -749266953 does not match master checksum: -1553442782.
Debug Message:  Successfully generated new font data file: C:\ProgramData\Stardock\Galactic Civilizations III\K2FontData_Normal.fontdata

So I deleted it all again and did a re-verify of the local cache and updated the 0.3H updates to the Game directory as well.

Did see a bunch of assault fighter error messages like

Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: TellariteAssaultFighter

[As far as I can tell besides size of Assault fighters - Klingon and Tellarites are defined as Tiny not Small matching Shipblueprint XML file -  there is something else wrong with assault fighters definition now.]

Debug Message:  CPlayerSystem::EndTurn m_currentTurnPlayerIndex = 0
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: ThalanAssaultFighter
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: DominionAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: RomulanAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: ArceanAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: CardassianAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: BorgAssaultFighter
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: ThalanAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: PirateAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: ThalanAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: DrenginAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: IconianAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: KrynnAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: AltarianAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: PirateAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: IconianAssaultFighter

Debug Message:  Ship Design: Missing ship design for ship class static blueprint ST_TerranStartingConstructor. Was this caused by pointing to a custom ship design? Blueprints must point to core or modded ships.

Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: TerranAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: PirateAssaultFighter
Debug Message:  RefreshFighterStats FAILED for AssaultFighterDesign. Could not find ship class: KrynnAssaultFighte

Seems to be issues with Klingon Tech Tree (I was playing Klingon)

Debug Message:  Building tech tree for node: KlingonEngineeringTech
Debug Message:  Building tech tree for node: KlingonImperialismTech
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  ERROR: GetTranslation() failed
Debug Message:  Building tech tree for node: KlingonWarfareTech
Debug Message:  TachyonSystem: Successfully retrieved match report response
Debug Message:  TachyonSystem: Successfully sent match report
Debug Message:  Building tech tree for node: KlingonCommunicationsTech
Debug Message:  ERROR: GetTranslation() failed

See a lot of these messages in the file - not sure why

Debug Message:  SoundSystem Error: MilesEvent: An asset requested by an event was not found in memory. : GC3_SFX_Bank/3D/3D_Objects/SHIPYARD_AMBIENT

Noticed Dilithium Crystal Graphic was missing and see some other error messages like sound files missing etc

and another strange message when processing the last player on the stuck turn last attempt

Debug Message:  RequestEndTurn PlayerObjectID 12, Turn #66 on net tick 0
Debug Message:  IGC3Player::RequestEndTurn playerID 12 on net tick 0
Debug Message:  IGC3Player::GetAndClearClickedRequestEndTurn 12
Debug Message:  CPlayerSystem::IterateCurrentPlayer to 7 on net tick 0
Debug Message:  IAIOpponent::UpdateAIMovePhaseJob PlayerID 14 on net tick 0
Debug Message:  CModifier::OnDestroyed modifierObjectID 24235
Debug Message:  CModifier::OnDestroyed modifierObjectID 24063
Debug Message:  CMobileListener::CMobileObjEvent_InitiateEjectShipsFromStation station 19059
Debug Message:  CMobileListener::CMobileObjEvent_InitiateEjectShipsFromStation ship 24062 does not exist
Debug Message:  CMobileListener::CMobileObjEvent_InitiateEjectShipsFromStation station 23576

[Edited to reflect current status of your 4.0 Alpha Mod]

One thing I noticed comparing your GST and Improved AI mod Shipblueprint.xml files to the stock Stardock version is that you assume the Carrier blueprint is for the Guardian Carrier modules - Stardock lets the drone carrier blueprint use either the Interceptor or Guardian Carrier module (you normally only get one or the other unless you trade for the one you are missing from someone else).  Difference between Carrier and Assault Carrier is the size (Carrier and Drone Carrier use the LARGE carrier hull - Aassault Carrier uses HUGE hull plus Stardock includes option to add the Escort Carrier module in addition to assault carrier modules in its Assault blueprint {fixed in latest update].  

Below is from the old July version of Stardocks standard ShipBluePrint.XML file

 <ShipBlueprint>
    <InternalName>DroneCarrierBlueprint</InternalName>
    <ShipHullType>Large</ShipHullType>
    <Role>Support</Role>
    <ShipGroup>Carrier</ShipGroup>
    <RequiredComponentType>InterceptorCarrierModule</RequiredComponentType>
    <RequiredComponentType>GuardianCarrierModule</RequiredComponentType>
    <ComponentType>BestDefense</ComponentType>
    <ComponentType>KineticWeapon</ComponentType>
    <ComponentType>MissileWeapon</ComponentType>
    <ComponentType>InterceptorCarrierModule</ComponentType>
    <ComponentType>LifeSupport</ComponentType>
    <ComponentType>BeamWeapon</ComponentType>
    <ComponentType>InterstellarDrive</ComponentType>
    <ComponentType>GuardianCarrierModule</ComponentType>
    <ComponentType>Sensor</ComponentType>
    <ComponentType>InterstellarDrive</ComponentType>
    <FillerComponentType>KineticWeapon</FillerComponentType>
    <FillerComponentType>BestDefense</FillerComponentType>
  </ShipBlueprint>
 
  <!-- Begin Blueprint -->
 
  <ShipBlueprint>
    <InternalName>CarrierBlueprint</InternalName>
    <ShipHullType>Large</ShipHullType>
    <Role>Support</Role>
    <ShipGroup>Carrier</ShipGroup>
    <RequiredComponentType>AssaultCarrierModule</RequiredComponentType>
    <ComponentType>BestDefense</ComponentType>
    <ComponentType>KineticWeapon</ComponentType>
    <ComponentType>MissileWeapon</ComponentType>
    <ComponentType>AssaultCarrierModule</ComponentType>
    <ComponentType>LifeSupport</ComponentType>
    <ComponentType>BeamWeapon</ComponentType>
    <ComponentType>InterstellarDrive</ComponentType>
    <ComponentType>AssaultCarrierModule</ComponentType>
    <ComponentType>Sensor</ComponentType>
    <ComponentType>InterstellarDrive</ComponentType>
    <FillerComponentType>KineticWeapon</FillerComponentType>
    <FillerComponentType>BestDefense</FillerComponentType>
  </ShipBlueprint>

Note you can use the Cargo Hull to make a cheap relatively defenseless escort carrier using either Assault, Interceptor, or Guardian Carrier Modules (can fit up to 3 carrier modules late game with DENSE attribute and all the mass increasing techs) but it will have little to no weapons and very little defense due to the low starting mass available with the Cargo Hull.

Also for all the fighters you have 3 sublight drives for assault and 4 for interceptor or guardian fighter blueprints as required modules.

[As you said this has been fixed now but you need to update what is included in the Improved AI mods which I was using till GST is fixed ]

I do like you changes to the fighter blueprints in the latest update - note that you may want to redo the Colony Constructor and Freighter Blueprints in your Improved AI Mod to reflect the changes you have made in GST.  I ended up with a late game award Colony ship with over dozen Sensors and only the default life support modules and there was similar prpblems with the other two.

 This seems excessive - Stardock includes one of each of the defense modules and then one sublight drive for the fighter blueprints after the appropriate weapons. 

I also notice that in the ShipClassDef.XML files you left the Interceptor Carrier module as favoring beam attack but it now uses kinetic weapons instead of beams in the blueprints.

[Wrong file name - not sure this affects anything but interceptors now use Kinetic not beams]

Also as reported by someone else - StarbaseModuleDef.XML file needs to be modified so that when you get High Capacity Carrier Tech that your Assault Fighter improvement to the starbase gives you Assault Fighters not interceptors.

 https://forums.galciv3.com/479893/page/1/#3653394

 <StarbaseModule>
 <InternalName>AssaultModule</InternalName>

  <Stats>
   <EffectType>AssaultFightersCap</EffectType>
   <Target>
    <TargetType>Starbase</TargetType>
   </Target>
   <BonusType>Flat</BonusType>
   <Value>5</Value>
  </Stats>

I can play as the federation just fine but if I add any ST AI characters; Romulans, Klingons, Dominion, etc the game crashes.  I can play a game fine with any stock AI on a map.

I reinstalled my game and no change. Added the update and the string overflow fix.

Here's a link to my debug file: http://detroitarchive.com/debug.txt

Thanks

I do not, is that required to play?

This is a fresh install with vanilla galciv3 latest version. 

Update: I purchased "Precursor Worlds" DLC and everything's working! Thanks!

Can't wait to play!