Register WPML on my mutisite Setup

This thread is resolved. Here is a description of the problem and solution.

Problem:
The client is attempting to set up the OTGS installer for WPML in two languages on a subsite of a multisite network but encounters a Curl 28 error during the registration process.
Solution:
1. Ensure that only the main site domain is registered on wpml.org. Subsites will use the same site key once the main site is registered. For detailed steps, refer to our guide on Multisite Support.
2. The Curl 28 error typically indicates a temporary connectivity issue. To resolve this, generate and register a new site key for your main site.
3. Contact your hosting provider to request whitelisting the following domains:

wpml.org
cdn.wpml.org
api.wpml.org
api.toolset.com
cloudfront.net

For more information, visit WPML plugin cannot connect to wpml.org.
If the problem persists, please open a new support ticket. We highly recommend checking related known issues (https://wpml.org/known-issues/), verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins.

For further assistance, please visit our support forum.

This is the technical support forum for WPML - the multilingual WordPress plugin.

Everyone can read, but only WPML clients can post here. WPML team is replying on the forum 6 days per week, 22 hours per day.

Tagged: Exception

This topic contains 3 replies, has 1 voice.

Last updated by Andrey 1 year, 1 month ago.

Assisted by: Andrey.

Author	Posts
April 4, 2025 at 1:53 pm #16897851
mandyT	<b>Background of the issue: </b> I am trying to set up the OTGS installer on the site for setting WPML in two languages on the subsite hidden link. This site is a child site of a multisite setup on hidden link. After installing the plugin OTGS installer, I encountered an issue. Kindly provide support for the bug as the license is active but not registering our site with WPML OTGS installer. Link to a page where the issue can be seen: hidden link. Screenshot: hidden link. Site Logins [removed] Page for register : hidden link. <b>Symptoms: </b> After installing the OTGS installer plugin, I received a Curl 28 error. I expected the site to register and install all the WPML plugins, but I am facing an issue with registering the license on the site. <b>Questions: </b> Why is the Curl 28 error occurring after installing the OTGS installer? How can I register the license on the site to install all WPML plugins?
April 5, 2025 at 11:38 pm #16900526
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	Hello, I would suggest you go to and remove https://wpml.org/account/sites/ from the list. On a Multisite, only the main site domain will need to be registered on wpml.org. You should register the main site first and then all subsites should use the same site key. Guide: https://wpml.org/documentation/support/multisite-support/#register-wpml-multisite The cURL28 error is usually only a temporary connectivity issue. In case further assistance is needed, please let us know. Best regards Andreas
April 7, 2025 at 4:21 pm #16905414
mandyT	Hello Andreas W., OTGS installer plugin still showing same error, on parent site. Please provide assistance for the issue as we are faceing it form to many days. Thanks
April 8, 2025 at 2:55 pm #16910124
Andrey WPML Supporter since 06/2013 Languages: English (English ) Russian (Русский ) Timezone: Europe/Kyiv (GMT+03:00)	I apologize for the trouble you've encountered. Please try generating and registering a new site key for your main site. Contact your hosting provider and ask them to whitelist the following domains: - wpml.org - cdn.wpml.org - api.wpml.org - api.toolset.com - cloudfront.net https://wpml.org/faq/wpml-plugin-cannot-connect-to-wpml-org/ If you are still experiencing the issue, please upload new screenshots. I have also removed the access credentials from your first message. Please consider changing them, as the support forum is public.