Hoi, I recently bought the Linux version of X3: Reunion from GOG, but I can't find a way to start it.

My system: Fedora 32, 64-bit version

I went via terminal into the X3 Reunion folder and started it by:


Which gave me:

./X3R_config: error while loading shared libraries: libgtk-x11-2.0.so.0: cannot open shared object file: No such file or directory

I looked in the folder /usr/lib/ and libgtk-x11-2.0.so.0 was there.

Then I thought, oh, I forgot to install the mentioned programs listed on the GOG page.

Which were:

Requires the following packages to be installed: libc6:i386 libasound2:i386 libasound2-data:i386 libasound2-plugins:i386 libgtk2.0-0:i386 libxml2:i386 and dependencies. This game comes with a 32-bit binary only

Through internet research I think I found the corresponding Fedora programs and installed them:

  • glibc-devel.i686, which installed libxcrypt-devel.i686 as dependency
  • alsa-lib.i686 (was already installed)
  • alsa-lib-devel.i686
  • alsa-plugins-pulseaudio.i686 (because pulseaudio was the only one installed in the 64-bit version I thought that would be the one for this game)
  • gtk2.i686, which installed atk.i686, gdk-pixbuf2-modules.i686 and jasper-libs.i686 as dependencies
  • libxml2.i686
  • libxml2-devel.i686, which installed cmake-filesystem.i686, xz-devel.i686, xz-devel.x86_64 and zlib-devel.i686 as dependencies

Then I tried to start the game again, this time I got:

./X3R_config: lib/libz.so.1: version `ZLIB_1.2.9' not found (required by /lib/libpng16.so.16)

Through some research I came to this site here: https://stackoverflow.com/questions/48306849/lib-x86-64-linux-gnu-libz-so-1-version-zlib-1-2-9-not-found

and tried the second solution:

cd /your_software/../lib/ (the directory containing libz.so.1)
mv libz.so.1 libz.so.1.old
ln -s /lib/x86_64-linux-gnu/libz.so.1

Because in Fedora is no lib/x86_64-linux-gnu/ I found out that the corresponding folder should be lib64

So I did:

cd /usr/lib/
sudo mv libz.so.1 libz.so.1.old
sudo ln -s /lib64/libz.so.1

Sadly this didn't help.

Recently I had a similar case with the Linux version of Mount & Blade: Warband from GOG, which gave me after start something like this:

error while loading shared libraries: libcurl-gnutls.so.4: cannot open shared object file: No such file or directory

But the solution for Mount & Blade: Warband was:

sudo ln -s /usr/lib64/libcurl.so.4 /usr/lib64/libcurl-gnutls.so.4

And Mount & Blade: Warband started after that normally.

Maybe that helps or will give an additional idea how to get X3: Reunion to start...

If I forgot anything I will add it, I only use Linux for browsing and some office / gaming, so when it comes down to it, I am only a beginner ;)

Thank you in advance.

Small update

So, I put the libz.so.1, which I compiled from source like @aphid showed it, into the ~/GOG Games/X3 Reunion/game/lib/ folder, but renamed the previous libz.so.1 to libz.so.1.old.

then I got:

Running X3: Reunion
Language detected: English
./X3R_config: symbol lookup error: /lib/libxcb-shm.so.0: undefined symbol: xcb_send_request_with_fds

which lead me to:


where someone had the same issue, but for X3 Terran War.

Well yeah, it's an other game, but the same series, so I thought the following might work:

Solution there was to delete the lib folder in the root folder of the game (that one next to docs, game, start.sh.,...) and keep in the lib folder located in games only with:


Of course I saved the ~/GOG Games/X3 Reunion/lib and ~/GOG Games/X3 Reunion/game/lib/ before doing this

which got me:

Running X3: Reunion
Language detected: English
libGL error: No matching fbConfigs or visuals found
libGL error: failed to load driver: swrast
X Error of failed request:  GLXBadContext
  Major opcode of failed request:  153 (GLX)
  Minor opcode of failed request:  6 (X_GLXIsDirect)
  Serial number of failed request:  107
  Current serial number in output stream:  106

which lead me with a search for failed to load driver: swrast to this:


So maybe 32-bit-nvidia-libs might help, or would they conflict with the current 64-bit-libs? X3: Reunion is a 32-bit only game afterall.

Currently installed ones which are 64-bit packages:


I would then just install the .i686 ones...

Or would this option be a dead end?

Update 2

Ok, installed now the 32-bit nvidia libraries and it starts now. Got help from here.

Also found out that it will start when you delete/rename the ~/GOG Games/X3 Reunion/lib folder. And you can keep all files in the ~/GOG Games/X3 Reunion/game/lib/ folder but we had to switch out the libz.so.1 with the previous compiled one.

I will write a detailed answer in the answer section to this now.

  • Nice that you found a solution to your own problem. Could you edit your question and answer your own question? By the way, when dealing with shared libraries/dependencies for programs that won't get updates at some point, you might want to create a separate library folder instead of messing around in the system library folder managed by your package manager (as it may create nasty dll hell conflicts). Also see superuser.com/questions/442178/….
    – aphid
    Commented Apr 16, 2021 at 17:13
  • @aphid Nah, it wasn't a solution for X3: Reunion, it was sadly only the solution for mount & blade: Warband and I thought I share this solution, so others might get an additional idea how to get X3: Reunion started, sorry. I will edit this in the question now... But if it helps others I could make a separate question for Mount & Blade: Warband and provide there the answer how to get it run on Fedora? Thanks for the link how to install multiple shared libraries, seems rather difficult for me, haven't done anything like that yet, are there any "noob-guides" out there?
    – Gubbel
    Commented Apr 18, 2021 at 19:08
  • 1
    [hpc.dtu.dk/?page_id=1180](Here's a good article) on how LD_LIBRARY_PATH works and what it does. (Note that your use case actually is one of the recommended ones: getting an older misnamed version of a library linked into your program, when you can't control the code in the program because it's closed source).
    – aphid
    Commented Apr 19, 2021 at 8:30

2 Answers 2


You should install zlib.i686 in addition to the regular zlib (x64), and (force) your game to link to it. It may work immediately, or you may have to use symlinks to get the game to load the correct library version.

The old version of zlib I need doesn't have an installer anymore, how do I install from source?

If the game is specifically looking for 1.2.9 (an obsolete version) then while we could try to utilize a newer version, this might cause bugs or crashes (although I guess that to be unlikely; this is a compression library which should want to be backwards-compatible). So there's no easy to install packages, which means you will have to compile the code yourself.

For that, you need a compiler. Take a look at the file Makefile.in. It contains all the instructions to compile the program. It also seems to be written in C, so we need a C compiler. I recommend installing either gcc or clang via your package manager if you don't have these already.

I recommend creating a working directory (in this example: ~/zlib129/). If you're paranoid, you can chroot into this directory to prevent any commands executed to compile code from affecting the rest of your system. Then commands to proceed would look like:

# Creates a directory to house the source code
mkdir ~/zlib129/
mkdir ~/zlib129/source/
# Create a directory to house the output of the compilation
mkdir ~/zlib129/chroot/
# Go into the directory
cd ~/zlib129/source/
# Download the zlib archive
wget https://zlib.net/fossils/zlib-1.2.9.tar.gz
# Extract it, skipping the root folder. 
tar -xvzf zlib-1.2.9.tar.gz --strip-components=1
# Let's check out how to compile it
nano makefile.in
### Read the instructions on how to compile...
make install prefix=/home/grubbel/zlib129/chroot/
### Move the library to where we want it. 
### One easy thing to just do is put it in the game's lib folder (if it has one preconfigured). 
mv ~/zlib129/chroot/lib/libz.so.1 /path/to/game/lib/libz.so.1

Note: If you manage to compile the library, but the game can't find it in its own folder, then try using the LD_LIBRARY_PATH environment variable trick from my comment.

The reason why your solution doesn't work:

System libraries typically come in two flavors, in addition to a host of versions. Typically these two flavors (64- and the older 32-bit) are put in different folders. Usually something akin to /lib versus /lib64. For historic reasons distributions don't have the same naming convention for this.

By symlinking to it, you are trying to load a 64-bit library into a 32-bit binary. This won't work, because the pointer sizes are different. Pointers are a thing that all C and C++ programs must use to pass variables (such as buffers with data or text in them) between eachother.

A pointer is a number pointing to a location in memory; the N-th byte in virtual memory. 32-bit (or i686, from the name of the ubiquitous 32-bit Intel processor series 286..386..486, etc.), programs, as the name implies, use pointers that are 32 bits in width, or 4 bytes. 64-bit programs, on the other hand, use pointers that are 64 bits in width, or 8 bytes.

So when zlib expects a pointer to a string to be zipped (compressed), it expects a 64-bit address. It would segmentation fault (the OS terminates programs that try to access nonexistent or unpermissable memory) and crash if you gave it a 32-bit address instead , as the other 32 bits would be filled with random garbage. The same goes the other way around: the game wouldn't be able to interpret a 64-bit address returned from the library because it wouldn't fit in the variable.

It's likely that your linker won't even let you do this and will loudly complain to you instead of letting your application halt and catch fire.

Why do I sometimes have to symlink these libraries?

The game wasn't made with the consideration in mind that one day there could be multiple pointer sizes in use on the same system. It also was made on a linux system where libraries may have been in /lib instead of /usr/lib, and this may have been hardcoded. There are a lot more linux distributions nowadays and conventions have changed. Things usually work but you may need to fiddle to get older programs to behave properly.

When it was programmed, 64-bit PC's didn't exist yet. As far as it is concerned, a pointer is a 32-bit unsigned integer. In fact, a lot of game developers get even this wrong and freely cast to signed ints, which is why a some older games crash as soon as they get to 2GiB memory and why Windows has a special flag that the programmer needs to set before a 32-bit app is allowed more than 2GiB memory.

  • thanks for the explanation, zlib.i686 was already installed, it was one of the dependencies mentioned in the question. Maybe it will work, when I somehow link the old ZLIB_1.2.9 to the game? I found it here: link, but I don't know how to proceed further.
    – Gubbel
    Commented Apr 19, 2021 at 14:30
  • 1
    That won't fit in a comment, but I can edit my answer with (untested) instructions on how to compile zlib. Since it's so old, that might not go flawlessly immediately (you may need old dependencies...), but you can try those.
    – aphid
    Commented Apr 20, 2021 at 16:02
  • whoa, thank you that was easy to follow. Now I am on the last step, where I have to put libz.so.1 into the game's lib folder. There are actually 2 folders called lib. One is /home/userName/GOG Games/X3 Reunion/lib/ and the other one is /home/userName/GOG Games/X3 Reunion/game/lib/ the later one has already a libz.so.1 file in it. Is the first path by the game preferred? So I should put it in there?
    – Gubbel
    Commented Apr 21, 2021 at 21:10
  • 1
    Checkout unix.stackexchange.com/questions/22926/… and stackoverflow.com/questions/2836330/… for a comprehensive overview of how to find out where and how linux programs look for libraries. You should be able to figure out what the game tries to load in.
    – aphid
    Commented Apr 22, 2021 at 9:07
  • thanks, I updated the question, because it would be visible more appealing there to read what I have done so far.
    – Gubbel
    Commented Apr 22, 2021 at 15:47

So, how I got X3: Reunion to run on Fedora:

1.) Install the following packages:

  which should install as dependencies:
  which should install as dependencies:
    atk.i686, gdk-pixbuf2-modules.i686 and jasper-libs.i686
  which should install as dependencies:
    cmake-filesystem.i686, xz-devel.i686, xz-devel.x86_64 and zlib-devel.i686 

2.) Get the older zlib version from here and compile it.

# Create a directory to house the source code
mkdir ~/zlib129/
mkdir ~/zlib129/source/
# Create a directory to house the output of the compilation
mkdir ~/zlib129/chroot/
# Go into the directory
cd ~/zlib129/source/
# Download the zlib archive
wget https://zlib.net/fossils/zlib-1.2.9.tar.gz
# Extract it, skipping the root folder. 
tar -xvzf zlib-1.2.9.tar.gz --strip-components=1
# Let's check out how to compile it
nano makefile.in
### Read the instructions on how to compile...
make install prefix=/home/YourUsername/zlib129/chroot/
### Move the library to where we want it. 
### But rename the old one first.
mv ~/GOG Games/X3 Reunion/game/lib/libz.so.1 ~/GOG Games/X3 Reunion/game/lib/libz.so.1.old
mv ~/zlib129/chroot/lib/libz.so.1 ~/GOG Games/X3 Reunion/game/lib/libz.so.1

3.) Install the nvidia 32-bit libraries or just your respective gpu driver 32-bit libraries, in this answer I will cover the nvidia one.


sudo dnf install xorg-x11-drv-nvidia-340xx-libs.i686 


sudo dnf install xorg-x11-drv-nvidia-libs.i686

the later one seems to be for newer gpus while the first one was for my gpu, I have a rather old one. If you should have an older gpu, too, but not the 340 version driver just replace the 340 with your version.

4.) Then delete the ~/GOG Games/X3 Reunion/lib folder or rename it and start the game.

And that's it, wish you a happy gaming.

Special thanks to aphid from here and PabloTwo from the FedoraForum.

sources of research were:





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