Try adding this to your entrypoint.sh

#!/bin/bash

a2dismod mpm_event

a2dismod mpm_prefork

apache2-foreground

If that dont work, just disable one:

#!/bin/bash

a2dismod mpm_event

apache2-foreground

Add the following command to your Dockerfile to disable the threaded MPMs (event and worker), forcing Apache to use mpm_prefork (which the PHP module requires).

You should place this command right after your RUN a2enmod rewrite command:

FROM php:8.2-apache

RUN apt-get update && apt-get install -y \

git \

unzip \

libzip-dev \

&& docker-php-ext-install zip mysqli pdo pdo_mysql \

&& apt-get clean && rm -rf /var/lib/apt/lists/*

COPY --from=composer:latest /usr/bin/composer /usr/bin/composer

WORKDIR /var/www/html

COPY . .

RUN chown -R www-data:www-data /var/www/html/web/app \

&& chmod -R 775 /var/www/html/web/app

RUN composer install --no-dev --optimize-autoloader

ENV APACHE_DOCUMENT_ROOT /var/www/html/web

RUN sed -ri -e "s!/var/www/html!${APACHE_DOCUMENT_ROOT}!g" /etc/apache2/sites-available/*.conf && \

sed -ri -e "s!/var/www/!${APACHE_DOCUMENT_ROOT}!g" /etc/apache2/apache2.conf /etc/apache2/conf-available/*.conf

RUN echo "upload_max_filesize = 1024M" >> /usr/local/etc/php/conf.d/uploads.ini \

&& echo "post_max_size = 1024M" >> /usr/local/etc/php/conf.d/uploads.ini \

&& echo "memory_limit = 1536M" >> /usr/local/etc/php/conf.d/uploads.ini \

&& echo "max_execution_time = 600" >> /usr/local/etc/php/conf.d/uploads.ini \

&& echo "max_input_time = 600" >> /usr/local/etc/php/conf.d/uploads.ini

RUN a2enmod rewrite

RUN a2dismod mpm_event mpm_worker || true

EXPOSE 80

COPY entrypoint.sh /entrypoint.sh

RUN chmod +x /entrypoint.sh

ENTRYPOINT ["/entrypoint.sh"]

2. If the Dockerfile Fix Fails (Debugging)

If the above fix doesn't work, the conflicting module must be loaded by a file copied in via COPY . . or in your entrypoint.sh.

You should check these two sources for explicit LoadModule directives:

1. Checkentrypoint.sh: If you are running a2enmod mpm_prefork or similar commands inside your entrypoint.sh after Apache has been initialized, remove it.

2. Check Configuration Files: Look for any custom Apache configuration files (e.g., in a local .apache/ directory that is copied into the container) that contain a LoadModule line for an MPM, especially if you are copying a full httpd.conf or a custom file that includes:

   • LoadModule mpm_event_module ...

   • LoadModule mpm_worker_module ...

You should only ever have one of the three MPM modules loaded. The php:8.2-apache image should take care of enabling the correct one (mpm_prefork), and the a2dismod command ensures any others are disabled.

I hope this helps!

I'm also having the same problem; I opened a support ticket just like yours. The problem started on Friday, December 12th.

Solution: "More than one MPM loaded" Error on Railway (PHP + Apache)

Problem Context

Hello! I had the same issue when deploying a PHP application on Railway using the

php:8.1-apache

image. The specific error was:

AH00534: apache2: Configuration error: More than one MPM loaded

This error occurs because multiple Apache MPM (Multi-Processing Module) modules are being loaded simultaneously, causing a conflict. Railway may automatically activate additional modules during deployment, generating this incompatibility.

Complete Solution

I was able to resolve this by creating a custom entrypoint script that disables all conflicting MPM modules and enables only

mpm_prefork

before starting Apache. Here's the step-by-step guide:

Step 1: Create the

docker-entrypoint.shScript

Create a file named

docker-entrypoint.shin the root of your project (or in your application's appropriate directory):

bash

#!/bin/bash

set -e

# Disable all MPM modules to avoid conflicts

a2dismod mpm_event 2>/dev/null || true

a2dismod mpm_worker 2>/dev/null || true

a2dismod mpm_prefork 2>/dev/null || true

# Enable only mpm_prefork

a2enmod mpm_prefork

# Start Apache in foreground

exec apache2-foreground

Script Explanation:

a2dismod mpm_*

: Disables all MPM modules that might be active

2>/dev/null || true

: Suppresses error messages if the module is already disabled

a2enmod mpm_prefork

: Enables only the

mpm_prefork

module (compatible with PHP)

exec apache2-foreground

: Starts Apache in foreground mode (required for Docker containers)

Step 2: Update the Dockerfile

Modify your

Dockerfileto copy and use the custom entrypoint. Here's a complete example:

dockerfile

FROM php:8.1-apache

# Install PHP extensions (adjust according to your needs)

RUN docker-php-ext-install pdo pdo_mysql mysqli

# Enable Apache modules

RUN a2enmod rewrite headers

# Set working directory

WORKDIR /var/www/html

# Copy application files

COPY . /var/www/html/

# Set permissions

RUN chown -R www-data:www-data /var/www/html

# Expose port 80

EXPOSE 80

# Copy and setup entrypoint script (fixes MPM conflict on Railway)

COPY docker-entrypoint.sh /usr/local/bin/

RUN chmod +x /usr/local/bin/docker-entrypoint.sh

# Start Apache via custom entrypoint

CMD ["/usr/local/bin/docker-entrypoint.sh"]

Important Points:

1. Adjust the COPY path: If your application is in a monorepo or subdirectory, adjust the

   COPY

   path as needed. For example:

   dockerfile

   COPY my-folder/docker-entrypoint.sh /usr/local/bin/

2. Execution permissions: The

   chmod +x

   is essential to make the script executable inside the container.

3. PHP Extensions: Adjust the

   RUN docker-php-ext-install

   line according to your project's needs (e.g., add

   curl

   ,

   gd

   ,

   zip

   , etc.).

Step 3: Deploy to Railway

After creating the files:

1. Commit and Push to your GitHub repository:

   bash

   git add Dockerfile docker-entrypoint.sh

   git commit -m "fix: Add custom entrypoint to resolve MPM conflict"

   git push origin main

2. Configure Railway to build from your repository

3. Deploy: Railway will automatically detect the Dockerfile and build

Deploying a base docker container (like Matomo) is crashing purely because of this issue. It seems to affect quite some people, I think it is quite bad that this happens especially since it has nothing to do with the container but purely the service Railway is supposed to offer.

I have the same problem. Locally the container works as expected. On Railway is crashing with the same error "AH00534: apache2: Configuration error: More than one MPM loaded.".