This site is not for solicitation of services or 'purchasing' development. Please do not post requesting side mods/plugins and so on. Your thread will be removed, and you will receive a warning.
I never use external moves (except for gather, rarely) so I never ran into this problem. However, I suspect that updating the forge version will wor,k, as SnowBlitzz and MoeBoy suggested. You get to keep your world and everything else.
See, forge updates to fix errors with its own code, but maintains compatibility with pixelmon so long as the minecraft version remains the same. So the newest 1.8.9 forge version (1.8.9 - 220.127.116.112) will work with the newest version of pixelmon (4.2.5).
Also, MoeBoy is right, you don't need to do a huge file replacement or anything. The first time you ran forge on your server it did everything you needed. Now, you just do what you did when you installed forge the first time:
You download the server version and dump the files somewhere you can easily access. You change the forge jar to custom18.jar, and replace only that file on the server. You should also update your personal (non-server version) to the newest forge. Even if you don't update the server, its still compatible.
If this doesn't fix your issue, I'd repost here, but I won't be able to help since I never experienced this problem. Good luck!