5.3.3

• autoload() inserts the debug toolbar middleware (DebugToolbarMiddleware, or DebugPanelMiddleware with DEBUG_PANEL) at the start of MIDDLEWARE, or right after GZipMiddleware when present, instead of appending it. Appended, it sat behind Django's page cache (UpdateCacheMiddleware ... FetchFromCacheMiddleware): responses without cookies were cached with the toolbar output (djdt-request-id, Server-Timing with SQL timings, or the full toolbar HTML) and served to every client, and cache hits bypassed the toolbar. A toolbar middleware already present in MIDDLEWARE keeps its position. Other extra middlewares are still appended. - show_toolbar fails closed, and system check codenerix.E001 reports it, when a toolbar middleware comes after a page cache middleware in MIDDLEWARE, with or without DEBUG_TOOLBAR_ALLOWED_IPS. This covers settings that add the page cache after calling autoload(), and Django's recommended UpdateCacheMiddleware before GZipMiddleware order, where the toolbar cannot sit both after GZip and before the cache.