Pro 20x account became unusable after upgrade — severe model degradation and persistent “Selected model is at capacity” errors

· Community Openai · Sept. 16, 2026, 6:45 p.m.
Summary
The blog post discusses issues encountered with a Pro 20x account after an upgrade, specifically focusing on capacity errors experienced by a subagent in the VS Code/Codex environment. It describes a situation where the parent agent managed tasks while a subagent faced 'Selected model is at capacity' errors but ultimately did not experience performance degradation. The author seeks to provide insights into diagnosing capacity errors that can affect delegated work.
AUTHOR