FML has found a non-mod file SimpleLogic-0.5.5.7.jar in your mods directory. It will now be injected into your classpath. This could severe stability issues, it should be removed if possible.

^noticed that in log only reference to simplelogic

Are you sure the latest version is for 1.12.2

Yes. You must have CharsetLib (or Charset) installed as well, at which point despite this warning the mod should be loaded properly (as part of Charset).