I’m having the same issue with the 1.8 update, and the link you provided relates to a theme called Hueman, and also a setting in Option Tree where “open in new tab” causes the issue. I can’t find a way to turn on or off “open in new tab” in the theme options, and if requires a hard-code theme change I’m concerned about that breaking with the next update. Can you assist further? I tried deactivating all plugins and the problem persisted. But based on what cgraf said above, I tried removing en_US.mo (since that should be my default) and the error went away (but I know that’s just a band-aid).
