2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/601We show that a certain class of flare models for variability from accretion disk coronae are subject to beam-plasma instabilities. These instabilities can prevent significant direct acceleration and greatly reduce the variable X-ray emission argued to arise via inverse Compton scattering involving relativistic electrons in beams and soft photons from the disk.4 pages, 0 figures, accepted for publication in A&A, uses A&A LaTeX macrosAstrophysicstext