Please include the FULL log of the server. You say that you have 137+ mods, however there is no way for us to know what mods you use by that pastebin, and that means that we can’t easily check if there is a known plugin/mod incompatibility. We also can’t check if this error is caused by something not initializing properly earlier on.
Please also let us know some of the server details, is this self-hosted? If not, what hosting company/plan?