Addendum:

Be sure to back up your WINEPREFIX in case a catastrophe happens! Also, you can copy your WINEPREFIX to another directory and log in as another character (read the rules, though! You can only have two active).

Thanks for all your hard work on this. Is there any way you could upload the compiled binary of xiloader, though?

Whenever I install FFXI in a virtual drive it wont load playonline............
Navigating to /.PlayOnLinux/wineprefix/FFXI/dosdevices/c:/Program Files/PlayOnline/SquareEnix/FINAL FANTASY XI/ and launching polboot.exe just causes an icon to appear and immediately disappear. Im using wine 1.3.37.

I think I'm just going to get a windows laptop because this isn't working

When I run Xiloader from terminal it asks me to login. I enter my username and password. It says

"err:ole:CoGetClassObject class {3501f5dd-7894-42df-866a-a2b6527d8049} not registered
err:ole:CoGetClassObject class {3501f5dd-7894-42df-866a-a2b6527d8049} not registered
err:ole:create_server class {3501f5dd-7894-42df-866a-a2b6527d8049} not registered
fixme:ole:CoGetClassObject CLSCTX_REMOTE_SERVER not supported
err:ole:CoGetClassObject no class object {3501f5dd-7894-42df-866a-a2b6527d8049} could be created for context 0x17

Failed to initialize instance of polcore!"

Thank you for your guide, it helped a lot.
I just want to add that with the new wine release 1.9.23 it is possible to easily run FFXI without the need of winetricks, only 2 'hacks' needed: patch dlls/imm32/imm.c as per your guide and get a winxp dxdiagn.dll (instructions on winehq appdb page for FFXI). You can use xiloader.exe from github without having to recompile,
Tried on Arch x86_64 succesfully.

Did you install using the 32 or 64 bit launcher?

I can't seem to get this to work on LInux, I'm running Ubuntu Gamepack 20.04 and followed all the instructions to a T the only think is it says to download things off the wiki page, but the wiki is down. and I get this error

0009:err:ole:CoGetClassObject class {3501f5dd-7894-42df-866a-a2b6527d8049} not registered
0009:err:ole:CoGetClassObject class {3501f5dd-7894-42df-866a-a2b6527d8049} not registered
0009:err:ole:create_server class {3501f5dd-7894-42df-866a-a2b6527d8049} not registered
0009:fixme:ole:CoGetClassObject CLSCTX_REMOTE_SERVER not supported
0009:err:ole:CoGetClassObject no class object {3501f5dd-7894-42df-866a-a2b6527d8049} could be created for context 0x17

Failed to initialize instance of polcore!
Closing...0009:fixme:vcruntime:__telemetry_main_return_trigger (00000000)

when trying to launch boot.exe