Visha Yogaविष योग
"Visha" means poison. This warning fires when the current Nitya Yoga (see "Yoga" above) is one of 9 classically toxic yogas — Vyatipata, Vaidhriti, Parigha, Vishkambha, Atiganda, Shoola, Ganda, Vyaghata, or Vajra.
Vyatipata and Vaidhriti are the two most severe (marked CRITICAL) and toxic for their entire duration. The other 7 are marked WARNING and are only toxic for a portion of the Yoga's span (anywhere from about 6% to 50% of it, depending on which Yoga) — the message shows the exact toxic window's start and end time, not the Yoga's full duration.
Each toxic Yoga has a known "toxic fraction" of its total duration, based on classical sources — e.g. Parigha is toxic for the first half of its span, while Vajra is toxic for roughly the first 6%.