Incantation of Ennervation has no AoE indicator and no effect until you've raised your incantation arcana level by at least 1. Also, Incantation of Defence (I think?) doesn't seem to improve with arcana levels.

Hello,

Thanks a lot for the report.

By any chance do you have a save where the problem occurs?

I'll try to look at this from my side but it will be very helpful.

I'll open a bug in our database if necessary.