reading the error:
... java.lang.NoClassDefFoundError: Lde/dosmike/spong e/languageservice/API/PluginTranslation;
I’d say you did not install LangSwitch. Looking at the mods forge loaded I’d say you did not install LangSwitch.
The first line in this topic sais this plugin requires LangSwitch.
Please tell me what else to do so people will read that. This is not meant to sound rude, I really don’t know what else to do for people to read that.