Mollie PHP 2.32.1 breaks all payments with 415 Unsupported Input Received

TL;DR

Downgrading to 2.32.0 fixed it immediately, which pointed at a regression in the release. A maintainer confirmed the regression and released 2.32.2 the same day to revert the bad change.

Steps

1. Updating mollie-api-php from 2.32.0 to 2.32.1 made every payment fail with 415: Unsupported Input Received, saying the API only accepts application/json or application/x-www-form-urlencoded. Downgrading to 2.32.0 fixed it immediately, which pointed at a regression in the release. A maintainer confirmed the regression and released 2.32.2 the same day to revert the bad change. Multiple users confirmed 2.32.2 worked as expected. One contributor also noted the Content-Type header casing was part of the problem in the meantime.
2. Version 2.32.1 shipped a regression that broke the Content-Type handling, so every API call failed with a 415. Fix: upgrade to 2.32.2, which reverts the bad change. Do not stay on 2.32.1. Several users confirmed payments worked again right after updating to 2.32.2. Source: https://github.com/mollie/mollie-api-php/issues/560

When to use

You are seeing this: Updating mollie-api-php from 2.32.0 to 2.32.1 made every payment fail with 415: Unsupported Input Received, saying the API only accepts application/json or application/x-www-form-urlencoded. Use this skill when you run into "Mollie PHP 2.32.1 breaks all payments with 415 Unsupported Input Received".

When not to use

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Versions

Versions mentioned in the source: 2.32.0, 2.32.1, released 2.32.2. If you are on something much newer or older, the details may have shifted.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Sources

• https://github.com/mollie/mollie-api-php/issues/560

Question: Updating mollie-api-php from 2.32.0 to 2.32.1 made every payment fail with 415: Unsupported Input Received, saying the API only accepts application/json or application/x-www-form-urlencoded. Downgrading to 2.32.0 fixed it immediately, which pointed at a regression in the release. A maintainer confirmed the regression and released 2.32.2 the same day to revert the bad change. Multiple users confirmed 2.32.2 worked as expected. One contributor also noted the Content-Type header casing was part of the problem in the meantime.

Verified resolution: Version 2.32.1 shipped a regression that broke the Content-Type handling, so every API call failed with a 415. Fix: upgrade to 2.32.2, which reverts the bad change. Do not stay on 2.32.1. Several users confirmed payments worked again right after updating to 2.32.2. Source: https://github.com/mollie/mollie-api-php/issues/560

Thread: https://vectle.com/threads/thr_WulEFuMZoschKwXHeuOPzg