[Resolved] Warning: Cannot modify header information ERROR

Hi there

Could you please try to isolate whether the problem arises through some conflict between WPML and something else?

Disable all plugins except for WPML, and switch theme to twentytwentyone.

Do the errors still occur?

If not, switch back to your normal theme, then re-activate plugins one-by-one, and after each step watch for the errors, and note reactivating which one triggers the problems.

Let me know what you find, thanks.

OK, good, we've narrowed it down.

Checking our list of recommended themes the Henrik theme doesn't appear to be listed as compatible (https://wpml.org/theme/?wpv_view_count=119967&wpv-theme-category=0&wpv_post_search=henrik&wpv-wpcf-recommendation-flag=&wpv_filter_submit=Search), although checking their ThemeForest listing they describe the theme as WPML compatible.

I would encourage you to contact the theme authors and invite them to join our compatibility programme, by sharing this link with them: https://wpml.org/documentation/support/go-global-program/

In the meantime we can take a look to see if the problem is straightforward and we can identify a solution.

Would you mind sharing zip files of the theme and plugin with me and I'll look into it further?

(You can paste dropbox or similar links here in the forum, they will be hidden from other users.)

It seems the Qode Framework plugin is required for the Henrik Core plugin to activate, do you have that, too?

Thanks for all of those links. I set up a test site and installed and activated everything, but I'm not seeing any problems in my debug log, so it seems like something more is needed.

Would it be possible to get a copy of your site for further testing?

You could use Duplicator or All in One WP Migration to create a package I can use to recreate your site locally. (If you are not familiar with either of them All in One is probably easier to use.) When creating the package, please exclude the media library to keep the file size down, it shouldn't be relevant to this issue.

Thanks for that. I managed to download it (!) and so I'll try to recreate your site locally and see if I can spot the problem. I'll get back to you when I've done that (Monday, I'm actually off today).

Good morning

I successfully installed the site copy locally.

I can't see the problem with the PHP warnings, though. I've navigated the back end and front end of the site, taking some actions like deactivating and reactivating plugins, but nothing triggers the PHP warnings you shared.

Are there some particular steps I should follow?

Also, could you please share your site debug info so that I can get some more details of your installation where this is happening?

See https://wpml.org/faq/provide-debug-information-faster-support/