First the easy solution:Start "pslaunch" and click "repair" (On windows you probably have to right-click the "PlaneShift" menu-item and start it with "Run as Administrator")

Now for those who for whatever reason don't want to use repair:
Linux:cat > /directory-to-PS-install/data/servers.xml << "EOF"
<serverlist>
<server name="Laanx server (Main)" description="Laanx server is our main server. All players are encouraged to engage in roleplay and stay In Character. If you are not much into roleplay, please be careful before speaking OOC with others.
Read our roleplay guide on PlaneShift main site!
Register at http://209.59.234.149/register" ip="209.59.234.149" port="7777" />
</serverlist>
EOF
In case of a global install (/opt) you probably will need a "sudo" in front of the "cat". And don't forget to change "directory-to-PS-install" to your actual install directory.
Windows:What a freaking nightmare...use repair! Ah...you don't like repair? Okay, I warned you...I couldn't figure out how the windows version of sudo works. Why do they have to make everything overly complicated?
First we need a command prompt as Administrator. So look for "Command Prompt" in your start menu, right-click it and "run as Administrator".
cd "C:\Program Files (x86)\PlaneShift\data"
(Might have to adjust this command in case of a different install directory or if you are using a 32 bit windows...or if the 64 bit PS client magically manages to install itself in the correct path for you)
echo ^<serverlist^> > servers.xml
echo ^<server name=^"Laanx server (Main)^" description=^"Laanx server is our main server. All players are encouraged to engage in roleplay and stay In Character. If you are not much into roleplay, please be careful before speaking OOC with others. >> servers.xml
echo Read our roleplay guide on PlaneShift main site! >> servers.xml
echo Register at http://209.59.234.149/register^" ip=^"209.59.234.149^" port=^"7777^" /^> >> servers.xml
echo ^</serverlist^> >> servers.xml
Now...close that command prompt immediately again! You got full admin privileges for that one so can cause some serious damage with it.
MacOS:Sorry, no clue about the toy-system. I guess it should work the same way as linux. Just start a shell (bash) and adjust the path to your install dir. Most likely you will need to "sudo" at the start to be allowed to write in the application folder.
Edit:And LOL...I should read the stuff I copy and paste...that can be always entertaining. OOC in main is allowed now as long as you are "careful?" Hahaha...