[Closed] PHP Fatal error: Uncaught InvalidArgumentException:

The issue seems to be caused by the usage of the last image inside the first container of your homepage:
hidden link

Title: sg4001 02bu 5
Attachment ID: 13506

Until now, I have sadly not been able to find out why this media file is causing an error, and I need to ask you for some more patience.

The cause for the error seems to be that you are using a Post Query Loop while calling an image that is not part of the current post.

If you set the dynamic image source {featured_image} for this image, it solves the issue. See screenshot.

This said, even if you see an error coming from WPML, then this might be expected in this case, as your Post Query Loop is using unexpected data that has no relation to the currently visualized post.

This was only related to "Uncaught InvalidArgumentException: Argument $language_code must be a non-empty string" - can you please confirm if this solved the issue on your live site?

Regarding:
"Api error missing resource: No sitekey found for this website"

You said you do not experience any issue with:
- Advanced Translation Editor
- Automatic translation
- Assignment or usage of credits
- Glossary or translation memory

This makes me think that this error might be a false positive.

Question:
Are you going to use automatic translation on both websites or only on the live site? Would this error require fixing on the staging site?

If you have the same error on your live site hidden link and the site does not operate as expected, then I need access to this site again, as none of the earlier provided credentials are allowing me to currently access the site.

Please go to WPML > Support > Troubleshooting and send me a screenshot of the section
"Your Automatic Translation account id is".

Further, please send me a screenshot from the current ATE Error Log at WPML > Support > ATE Error Log.

Also, please revise WPML > Support > Installer Support and click "Check now". Revise if the API connections and site key registration are working as expected.

Finally, if possible, please confirm if the following features work as expected:
- Advanced Translation Editor
- Automatic translation
- Site Assignment or usage of credits
- Glossary or translation memory

This seems to be a false positive, as on the system, it all looks correct.

Can you please confirm at WPML > Translation Dashboard > Translation Tools that the site currently has 41112 credits available?

In this case, I would suggest that for now, you can ignore this error, as long as the site operates as expected.

I am escalating the issue to the second-tier support for further revision.

Please let us know when we can take a look at the live site, in case further assistance is needed.

The second-tier support informed that the issue on your site can only get solved in the following way:

1) Go to https://wpml.org/account/websites/

2) Delete the site URL from the list.

3) Now enter the site URL again. This will create a new site key.

4) Click "Show key" and copy it.

5) Enter the key under Plugins > Add New > Commercial (tab) to re-register WPML. If WPML is already registered here, unregister it first.

If the problem persists after registering WPML with a new site key, please let me know.

Our apologies for the inconvenience!

If those steps do not solve the issue, please let me know.