u/fnm1900

Setup:

• REAPER 7.71, Windows 10
• M-Audio M-Track 2x2, ASIO driver
• Sample rate: 48kHz across all settings (project, interface, driver panel)

Symptom: Play cursor appears but doesn't move. No audio output. Happens only on existing projects — new projects play fine. Other apps (iZotope RX, YouTube) work normally.

What I've tried:

• Matched sample rate across project settings, audio interface, and ASIO control panel
• Switched audio systems: ASIO → WASAPI → DirectSound — all fail on existing projects
• Reinstalled M-Audio ASIO driver
• Changed USB port, rebooted
• Reinstalled REAPER (didn't help — config files in %APPDATA%\REAPER persisted)
• Wiped %APPDATA%\REAPER entirely and reset — new projects now work, but existing .rpp files still don't play

Current suspicion: Something baked into the existing .rpp files is blocking the audio engine. Not sample rate — already checked. Could be a plugin/FX issue?

Question: What inside an .rpp file could cause the audio engine to stall on playback? Any way to diagnose or strip the problematic setting without rebuilding the project from scratch?