Correction - Reductive subgroup schemes of a parahoric group scheme

In the published version of the manuscript “Reductive subgroup schemes of a parahoric group scheme”, the proof of Theorem 4.5.6 is flawed and should be corrected as described here.

I would like to thank Anis Zidani for bringing the flawed proof to my attention, and for critical comments on some preliminary attempts to fix the error.