500 Internal Server Error on AMI upgrade due to password mismatch
AMI upgrade causes 500 errors due to password mismatch between Plack and MySQL.
- Published
- May 28, 2026
- Last Updated
- May 29, 2026
- Affected Versions
- Koha AMI builds released before 2026-05-29
- Fixed In
- Koha v25.11.04-1 (AMI build 2026-05-29)
Overview
After upgrading to a new Koha AMI, customers may experience a 500 Internal Server Error on every request. This occurs because the Plack service starts before the persistent data volume is mounted, causing it to cache an incorrect password. MySQL, however, expects the old password from the data volume, leading to the error.
Affected Versions
- Koha AMI builds released before 2026-05-28.
Remediation
Option 1: Upgrade to Patched AMI
When a patched AMI is available on AWS Marketplace, launch a new instance from it and migrate your data. See the migration guide for step-by-step instructions.
Option 2: Apply Interim Mitigation
No interim mitigation is available. Upgrade to the patched AMI when released.
Option 3: Contact Support
If you are unsure how to apply the above steps, contact us at [email protected] or use the contact form. We can walk you through the fix remotely.
Timeline
| Date | Event |
|---|---|
| 2026-05-28 | Issue identified |
| 2026-05-28 | Advisory published |
| 2026-05-29 | Patched AMI published to AWS Marketplace |