[Closed] I am experiencing an issue after setting up WPML on a website (500 Internal Server Error.)

Hello WPML Support Team,

I am experiencing a persistent issue with WPML on my staging site:

Staging site URL: hidden link

Whenever I try to access certain pages, especially /en/wp-json/ or /en/test-wpml/, I get a 500 Internal Server Error.

The Apache error log shows the following message:

[core:error] [pid 39635:tid 39635] [client 94.253.188.89:12148]
AH00124: Request for staging2.luminx.no:/home/u3-ds6phfvu4ix1/www/staging2.luminx.no/public_html
exceeded the limit of 10 internal redirects due to probable configuration error.
Use 'LimitInternalRecursion' to increase the limit if necessary.
Use 'LogLevel debug' to get a backtrace.

I suspect this is caused by a redirect loop related to WPML language directories (/en/, /no/).

Here is the current .htaccess configuration on the staging site:

# BEGIN HTTPS forced by SG-Optimizer
<IfModule mod_rewrite.c>
RewriteEngine On

# Force HTTPS
RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^ hidden link{HTTP_HOST}%{REQUEST_URI} [L,R=301,NE]
</IfModule>

# BEGIN Custom WPML login redirects
<IfModule mod_rewrite.c>
RewriteEngine On
# Redirect WPML login pages to main wp-login.php
RewriteRule ^en/wp-login.php$ /wp-login.php [QSA,L]
RewriteRule ^no/wp-login.php$ /wp-login.php [QSA,L]
</IfModule>

# BEGIN WPML REST API fix
<IfModule mod_rewrite.c>
RewriteEngine On
# Prevent /en/wp-json/ or /no/wp-json/ from redirect loop
RewriteCond %{REQUEST_URI} ^/(en|no)/wp-json/ [NC]
RewriteRule ^ - [L]
</IfModule>

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /

RewriteRule ^index\.php$ - [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

Additional info:

WordPress version: 6.9.1

PHP version: 8.2

Server: Apache, Linux

Plugins active: WPML Multilingual CMS, WPML String Translation, SG-Optimizer, and others

I have already attempted adjustments to .htaccess, but the problem persists, particularly affecting REST API endpoints (/en/wp-json/).

Could you please advise on:

Correct .htaccess configuration to prevent internal redirect loops with WPML?

Any WPML settings that could be causing the loop?

Steps to make /en/wp-json/ and other language-prefixed REST endpoints work without generating a 500 error.

Thank you for your support.