AS2 Decryption Failed: Fixing Certificate and Algorithm Mismatches
Fix the AS2 decryption-failed MDN error: wrong certificate after rollover, key mismatch, 3DES vs AES conflicts, corrupted PKCS#7, and wrong certificate purpose.
8 min read
AS2 Testing Blog
Expert guides on AS2 connection testing, certificate management, EDI compliance, and troubleshooting common AS2 issues.
Your Trading Partner Says Their Cert Is Fine. A Field Guide to Proving Who's Actually Wrong
When an AS2 connection fails, both sides insist their config is fine. Here's the elimination method for producing evidence instead of assertions.
9 min read
AS2 HTTP 401 and 403 Errors: Authentication Fixes That Actually Work
Fix AS2 HTTP 401 Unauthorized and 403 Forbidden errors: missing basic auth, IP allowlists, wrong AS2-From/AS2-To IDs, TLS client certificates, and wrong URL paths.
8 min read
AS2 insufficient-message-security Error: 5 Causes and How to Fix Each One
Your MDN came back with processed/error: insufficient-message-security. Diagnose missing signing, missing encryption, weak algorithms, and silent partner policy changes.
7 min read
AS2 MDN Not Received: Why Your Receipt Never Arrives and How to Fix It
Your AS2 message sends fine but no MDN comes back. Diagnose missing MDNs: async receipt URL issues, firewall blocks, sync timeouts, DNS failures, and more.
12 min read
AS2 Connection Failed: The Complete Troubleshooting Guide
Fix AS2 connection errors fast. Covers TLS handshake failures, HTTP errors (401, 403, 502), timeouts, DNS issues, cipher mismatches, and payload errors with exact commands.
14 min read
How to Fix AS2 Certificate Errors: A Practitioner's Troubleshooting Guide
Diagnose and fix the most common AS2 certificate errors, from expired certs to format mismatches. Practical steps with OpenSSL commands you can run right now.
11 min read
Stuck Between Two VANs: 15 Days to Fix a 2-Minute Config Change
When your VAN says 'our side is fine' and your partner's VAN says the same thing, you're the one stuck in the middle. Here's how to break the deadlock before it costs you $4,800 and three weeks.
8 min read
MDN Verification Failed: Fix It in Minutes, Not Hours
60% of MDN failures are algorithm mismatches. Here's how to diagnose AS2 MDN errors, sync/async confusion, signature verification, MIC mismatches, and fix them fast.
9 min read