Hotfix for yesterday's v0.21.0 — most importantly for the auto-updater crash some of you hit within hours of the release (#90, #94). Sorry about that one; it was as bad as bugs get, and the reports were superb. Details below, but the short version: install this release manually (download the zip for your engine, close the editor, replace Plugins/Monolith/ in your project). Building from source? Just pull master.

Fixed

• CRITICAL — clicking "Install" on the update notification no longer crashes the editor on Windows (#90, #94). Since v0.14.7 the updater's integrity check called FPlatformMisc::GetSHA256Signature, which has no Windows implementation — the engine's generic fallback is a fatal assert, so the check killed the editor the moment it ran. It now uses a portable, NIST-vector-tested SHA-256 built into the plugin, and release checksums moved to Monolith-SHA256-v2-* marker names so older (broken) updaters can never trip over them again. Thanks @Alexbeav for the minidump-verified root cause (#90) and the fix (#91), and @SilkroadLabs for the parallel report (#94).
• blueprint add_event_dispatcher now creates the multicast delegate member variable (mirroring the Blueprint editor's own flow), so CallDelegate / AddDelegate / RemoveDelegate can actually bind the dispatcher; remove_event_dispatcher cleans it up too. Thanks @Alexbeav (#84).
• blueprint add_node / resolve_node with node_type: "SpawnActor" no longer crash the editor — the bare name aliases to SpawnActorFromClass instead of instantiating the legacy node whose title code null-derefs, and generic-fallback nodes report a safe title. Thanks @Alexbeav (#85).
• blueprint add_timeline_track — the new track's output pin now actually appears on the timeline node and is connectable (display-track registration + node reconstruction, mirroring the timeline editor). Thanks @Alexbeav (#86).
• blueprint batch_execute honors a top-level graph_name as the default for every op (per-op values still win) instead of silently editing the EventGraph. Thanks @Alexbeav (#87).
• blueprint resolve_node dry-runs of delegate nodes now resolve the real signature pins instead of just execute/then/self. Thanks @Alexbeav (#92).
• Array/object params sent as JSON-encoded strings now work everywhere — some MCP clients (Claude Code included) stringify complex tool arguments; the registry now recovers them centrally, so flat calls to delete_assets, save_packages, set_function_params, set_event_dispatcher_params, etc. stop failing with "array is required". Thanks @Alexbeav (#93).

Added

• editor load_level fail-closed guards — refuses when the current map has unsaved changes that the unattended load would silently discard (override with dirty_policy:"discard"), and refuses when a stale in-memory copy of the target world would trip the engine's fatal "World Memory Leaks" assert. Thanks @Alexbeav (#89).
• Paired MODAL_OPEN / MODAL_CLOSE editor-log telemetry with window identity and slow-task flag on UE 5.8+, so log consumers can tell a healthy modal from one still blocking the game thread. Thanks @Alexbeav (#88).

Huge thanks to @Alexbeav for an exceptional batch of contributions — nine merged PRs in this release, every one tested and documented to a standard that made review a pleasure.

Monolith-SHA256-v2-UE5.7: cce5ad20f43e466af8d54f5ef6a80b57c1fed5e689984ddb76f739daf11db3c4
Monolith-SHA256-v2-UE5.8: 75d1ec92d73fe6142827da8f157e433ae90b2e7596947a990406440247c64b1a
Monolith-SHA256-v2: cce5ad20f43e466af8d54f5ef6a80b57c1fed5e689984ddb76f739daf11db3c4