I've noticed that there are some games on GOG that have official overlay support but it isn't working.
The reason for this is a wrong setting made by the developers of these games. It happens mostly with games that use Unreal Engine 4 & 5. I've contacted the devs about this issue and some have replied, they'll fix it with the next update but that rarely happened. So i made the decision to open this thread and post fixes for that problem. These fixes are just simple config files that i've edited with Notepad and you can use them only for the Windows versions.

Here are the games where i've noticed this. Click on the title to download the fix and read below how to install it.

• A Juggler's Tale
• Aquanox Deep Descent
• Asterix&Obelix XXXL: The Ram From Hibernia
• A Tale of Paper: Refolded
• Bang-On Balls: Chronicles
• Beyond a Steel Sky
• Caravan SandWitch
• Chernobylite
• Dark Fracture: Prologue
• Desperados III
• Dungeons 3
• EVERSPACE 2
• Evil West
• Firmament
• Kingdoms of Amalur: Re-Reckoning
• Layers of Fear (2023)
• Martha Is Dead
• Mortal Shell
• Myst (2021)
• Neighbours Back From Hell
• N.I.C.E. 2
• Nymphomaniac - Sex Addict (incl. achievements fix)
• PARANOID
• Priest Simulator: Vampire Show
• Pumpkin Jack
• Raji: An Ancient Epic
• RoboCop: Rogue City
• Rough Justice: '84
• Sapphire Safari
• SCARF
• Seven: Enhanced Edition
• SlavicPunk: Oldtimer
• Stray Gods: The Roleplaying Musical
• Succubus
• System Shock (Remake) (incl. achievements fix)
• The Citadel
• The Expanse: A Telltale Series Deluxe Edition
• The Thaumaturge
• The Uncertain: Light At The End (Version 1.5)
• Tintin Reporter - Cigars of the Pharaoh
• Trials of Fire
• Troublemaker
• Warhammer 40,000: Dakka Squadron - Flyboyz Edition

Special cases:

• Saints Row IV: Re-Elected - No EOS overlay fix (INT + AU)
This will launch the Re-Elected version without installing Epic Online Services but working overlay. The archive contains overlay fixes for both, the international version as well as the Australian version. Just open the folders with your edition and preferred language and install the fix as described below.

• Prison Architect - No Paradox launcher overlay fix
This will bypass the Paradox launcher and start Prison Architect directly from its executable with working overlay.

• Vampire: The Masquerade - Bloodlines 2 - No Paradox launcher overlay fix
This will bypass the Paradox launcher and start Vampire: The Masquerade - Bloodlines 2 directly from its executable with working overlay.

• The Entropy Centre - Achievements fix
This fixes the Galaxy achievements which are completely broken with the latest version of the game.

• The Beast Inside - Achievements fix
This fixes the Galaxy achievements of The Beast Inside.

• El Paso, Elsewhere - Achievements fix
This fixes the Galaxy achievements which are completely broken with the latest versions of the game.

+++

How to install an overlay fix:

1. Exit Galaxy. (Close it completely)
2. Extract the downloaded file into the game's installation folder and overwrite the existing one.
3. Now move the whole installation folder to a directory on the same partition where Galaxy isn't looking for your installed games (In my case i moved it to the desktop)
4. Restart Galaxy.
5. Move the installation folder back to where it was before.
6. Search for the game inside Galaxy. (It'll show as not installed)
7. Right click on the game's cover, "Manage installation" and "Import folder". Select the game's folder and add it to Galaxy again.
8. Start the game and enjoy it with a working overlay.

If you know more games with that issue, please let me know. You can check if a game supports the overlay by opening the game's configuration in Galaxy. Look at the attached screenshots.

If you want to try if the overlay is working on unsupported games, you should take a look at this thread:

Galaxy overlay tests and reports for unsupported titles

Great guide thanks! Too bad these developers are somewhat unwilling to fix these simple bugs.
If I find other games affected by this bug I will report them here.

Gateway Trilogy Overlay is not working. Any idea how to fix it?

"{
"buildId": "53391118460173654",
"clientId": "53272545291458283",
"gameId": "1754024564",
"language": "English",
"languages": [
"en-US"
],
"name": "The Gateway Trilogy",
"playTasks": [
{
"category": "launcher",
"isPrimary": true,
"languages": [
"en-US"
],
"name": "The Gateway Trilogy",
"path": "steamwrapper.exe",
"type": "FileTask"
},
{
"category": "game",
"isHidden": true,
"languages": [
"en-US"
],
"name": "The Gateway Trilogy - launcher process gateway_exe",
"path": "gateway.exe",
"type": "FileTask"
}
],
"rootGameId": "1754024564",
"version": 1
}"

Latest additions:

Chernobylite
Unbound: Worlds Apart

Added:

Pumpkin Jack

Removed:

Unbound: Worlds Apart - fixed by the developer with the latest update

Dude. You be doing GOG's job. I'm not effected; I wouldn't touch Galaxy with a shitty stick. But I'm sure your efforts are appreciated. +rep.

Added:

Severed Steel

Added:

A Juggler's Tale

Added:

Succubus

Removed:

Severed Steel - fixed by the developer with the latest update

deleted

Added:

Desperados III

what are these overlays good for?

Features of the Galaxy overlay:

Chat window
FPS counter
Screenshots (F12)
Achievement pop-ups

Added:

Firegirl: Hack 'n Splash Rescue