The Eclipse bar has changed quite a bit how it works on the beta, I haven't looked at it too closely myself, but one thing to note as of the more recent builds is that both of the two buffs that oUF uses to detect which eclipse the player has are now deprecated, and results in an error if the element is used.

I'm aware that the work on updating oUF to 6.0 has yet to be started, but I'll leave this here as a head's up.

Oh, and adding issue labels for WoD would be nice.

No idea if this breaks other stuff, but it stopped the Eclipse Bars erroring and seemed to updated OK .. I changed lines 50 and 51 to (as I couldn't find the constants):
local ECLIPSE_BAR_SOLAR_BUFF = GetSpellInfo(164725)
local ECLIPSE_BAR_LUNAR_BUFF = GetSpellInfo(164724)

Changes from build 18414 (live) to build 18764: https://gist.github.com/p3lim/50d1c71711297142e082/revisions