Troubleshooting

Login & Account

“Invalid credentials” — Check username/password and Caps Lock.

“Device limit reached” — Revoke an old device from Settings → Account. A 12-hour cooldown applies before a new device can register.

“License expired” — Renew at krantz.run. No grace period — access stops immediately on expiry.

Lost password — We do not store your password and cannot recover your account. Keep your credentials in a password manager.

Checking Issues

High “Connection Failed” rate — Check internet connection, verify proxies work, reduce thread count, try without proxies.

Many “Rate Limited” results — Reduce threads, add more proxies, switch to residential proxies.

“Server Not Found” — The domain doesn’t exist or has no mail server configured.

Slow speed — Increase threads (up to 2,000 on Pro), use faster/more proxies.

Proxy Issues

“Proxy Error” on all checks — Verify format (host:port or user:pass@host:port), test proxies manually, check proxy authentication.

Rate limited despite proxies — IPs may be flagged. Use residential proxies, add more, lower thread count.

App Won’t Start

• Windows: Install Visual C++ Redistributable
• Linux: sudo apt install libwebkit2gtk-4.1-0
• Antivirus: Add an exception for the krantz binary and installation directory
• Reinstall: krantz update mail or krantz update sorter

Crashes

Reduce thread count, check available RAM, update: krantz update.

Legal Use

Krantz is intended strictly for legal purposes — processing data you own or have explicit written authorization to test. You are solely responsible for how you use the software. Unauthorized use may result in immediate license termination.

Contact

Reach support at krantz.run.