Ensure you have a clean install of X3 Albion Prelude. A clean install is one that:
Is updated to the latest version.
Has never had any mod/script installed to it or any mod tool associated with it. This is key. Mod tools like plugin manager will break your install and you can never be completely sure that previously installed mods/scripts have had every file associated with them removed or reverted to the vanilla version. When in doubt, delete your entire installation folder and reinstall from scratch.
Create an install of X3AP separate from the one downloaded from Steam/GOG.
Find the folder your game is installed in. For a fresh Steam X3AP install, this is located within your steam folder in ...\Steam\!SteamApps\common\x3 terran conflict. For the GOG version it could be C:\GOG Games\X3 Terran War Pack
Copy the x3 terran conflict (or X3 Terran War Pack for GOG version) folder to another location. In my install I used ‘C:\X3’, but any location not associated with Steam (or GOG Galaxy) will do.
Do one (and only one) of the following:
Steam Only: Download the NoSteam executable from the Egosoft website and extract it to your new x3 terran conflict folder. You will need to log into the Egosoft website, and register your CD-Key with your forum profile to access the executable.
GOG Only: Inside the copy of X3 Terran War Pack remove the file addon/t/gamestarts.pck if present.
Update any shortcuts you use to point to X3AP.exe.
Ensure X3AP is set to use English localization.
Create a shortcut to the x3ap.exe file.
Right click on the shortcut and click properties.
On the Shortcut tab, locate the Target text box.
Paste -language 44 at the end of the current contents of that text box.
For example, the Target line for your shortcut may read "C:\X3\X3AP.exe" -language 44