How to Fix PS2 Games Not Launching from ES-DE on the Retroid Pocket 6

Causes

• The Storage Access Framework URI handoff fails — when you launch a PS2 game from ES-DE, the frontend hands NetherSX2 the game as a content:// URI instead of a plain file path. NetherSX2 can only read that URI if it holds a persistent folder grant for the folder the game lives in. Without the grant, the game silently fails to boot from ES-DE even though the exact same game runs fine when opened inside NetherSX2 — the classic "works in the emulator, not from the frontend" symptom.
• NetherSX2 has no storage permissions to grant — NetherSX2 is Storage Access Framework-only by design and declares no storage permissions, so the usual fix of granting "all files access" in Android settings does nothing. The RP6 emulation guide explicitly notes that an appops permission grant no-ops on NetherSX2 — the only thing that works is a folder grant picked inside the app itself, which most users never do.
• The emulator was set over ADB or by editing files, so ES-DE ignores it — ES-DE rewrites its gamelists and drops externally-injected edits, so an alternative PS2 emulator (or per-system core choice) configured by editing files or pushing settings over ADB never sticks. ES-DE keeps launching the wrong or a stale emulator, and the game dies on startup. The alternative emulator must be set in ES-DE's UI to be honored.
• A stale game directory in NetherSX2 — if a specific game hangs at startup with a FileHelper.findFiles crash in the log, NetherSX2 has a stale game directory pointing at a folder that no longer exists (for example, after moving ROMs to a new SD card). The emulator trips over the dead path before it ever reaches your game.
• Missing or incorrectly named PS2 BIOS — NetherSX2 needs a PS2 BIOS file (for example, a SCPH-70004-family BIOS) in its BIOS folder, named exactly as the emulator expects. Without it, games can appear to launch and then immediately drop back to the frontend, or show a black screen, which users often misreport as "the game won't start."
• An unsupported or damaged ROM format — NetherSX2 is pickiest about plain .iso dumps. Multi-file .bin/.cue sets with a mismatched cue sheet, zipped archives, or a truncated download will fail to boot reliably from either ES-DE or the emulator itself.

How to Fix

1. Confirm the game runs inside NetherSX2 first — open NetherSX2 directly (not through ES-DE), navigate to your ROMs/ps2 folder, and launch the game. If it boots here, the problem is the frontend handoff and the fix is the folder grant in step 2. If it fails here too, skip to the BIOS and ROM checks in steps 4 and 6.
2. Add your PS2 ROM folder as a game directory inside NetherSX2 — in NetherSX2's own UI, go to the game directory settings and add ROMs/ps2 through the folder picker. The picker grant is what matters — it gives the app the persistent Storage Access Framework permission it needs to read content:// URIs handed over by ES-DE. After this single step, games launched from ES-DE boot. Re-add the directory if you ever move your ROMs to a new card.
3. Set the PS2 emulator in ES-DE's UI, not in files — open ES-DE and go to Menu → Other Settings → Alternative Emulators, choose PS2, and select NetherSX2 (or ARMSX2). Make the change in the UI rather than by editing config files — ES-DE rewrites its gamelists and silently drops file-based edits, which is why your ADB-injected emulator choice kept reverting.
4. Verify the PS2 BIOS is present and correctly named — in NetherSX2, check the BIOS settings screen and confirm a BIOS file is listed. If not, copy a PS2 BIOS dump into NetherSX2's BIOS folder using the exact filename the app expects, then re-check the BIOS screen until it shows as detected. A game that "launches then bounces back" is almost always missing BIOS.
5. Fix or remove stale game directories — if a particular game crashes at startup with FileHelper.findFiles in NetherSX2's log, open the game directory settings and remove any entry pointing at a folder that no longer exists (a common leftover after migrating ROMs between SD cards), then re-add your current ROMs/ps2 path.
6. Re-dump or convert the game to a clean .iso — re-rip problem discs to a single .iso file (or convert .bin/.cue sets with a tool like IMGBurn), and don't keep PS2 games inside zip archives. Verify the file size matches the disc size — a truncated download is the most common cause of a game that boots to a black screen and dies.
7. Update NetherSX2 or switch to ARMSX2 — if games still fail after the folder grant, update NetherSX2 to its latest build, or install ARMSX2, the newer PCSX2-based PS2 emulator, and select it in ES-DE's Alternative Emulators. ARMSX2 reads the same ROMs and handles some games NetherSX2 versions struggle with on the RP6's Adreno 740.
8. As a last resort, reset NetherSX2's data and re-grant — go to Settings → Apps → NetherSX2 → Storage, clear its data (back up your save states and memory cards first — they live in the app's data folder), then re-add the game directory from step 2. This clears any corrupted grants or directories that survive the settings screen.