Horizon Launcher Not Working? Fixes for Crashes, Black Screens and Stuck Prepare

When a launcher misbehaves, the internet offers forty fixes in no order. This page offers the ones that work, in the order they work, for the build from horizon launcher App. Start at the top; most readers will be playing again before the third fix.

Black screen or crash on launch: swap the renderer

Nine first launch failures in ten are the renderer. Open Settings before launching and switch pipelines: from Vulkan to OpenGL ES on older phones, or back if you changed it earlier. The wrong pipeline for your GPU shows up exactly like this: black screen, instant crash, or flickering textures.

The swap touches nothing else. Worlds, settings and mods are untouched by the rendering path, so this fix is free to try and free to reverse. the Vulkan or OpenGL ES guide explains the choice in depth if you want the why behind the what.

Prepare run stuck or failed: the three checks

Check storage first: a nearly full phone stalls preparation silently. Check connection second: preparation fetches what it needs and hates interruptions. Check battery management third: aggressive power saving that puts the app to sleep mid run is the classic hidden cause.

Then simply run preparation again. The launcher reuses what already prepared cleanly, so a retry is rarely a full repeat. the prepare guide walks the whole step if you are meeting it for the first time.

Problems right after an update

Let the launcher finish everything it started: pending preparations and build updates complete in the Versions page, and launching mid housekeeping creates half the post update bug reports we see.

If a specific build misbehaves after updating while an older build behaves, play the older build and keep the new one installed; the shelf design means a bad week for one build never strands your worlds. Never uninstall the app to fix a build; that trades a small problem for a large one.

A world will not open

Confirm the build you are launching matches the world: a modded world wants its build and its mod list present. Confirm the save itself in the Java game if doubt remains, because saves are vanilla format and the Java client is the perfect second opinion.

A world that opens in Java and not in one Horizon build is a build problem, not a save problem, and it is solved by the shelf: another build, or the same build after its next update. Your save is almost certainly fine.

Tested on our own Android phones with the current build, like every guide on this site. If a step behaves differently on your device, tell us through the contact page and the guide gets corrected, not defended.