After a simple update on my form, the sender gets the following message:

our form could not be submitted for the following reason(s):

Warning: [ err 2/line 1798/PHPMailer.php] popen() has been disabled for security reasons
Warning: [ err 2/line 1798/PHPMailer.php] popen() has been disabled for security reasons
Could not execute: /usr/sbin/sendmail -t -i -f jochemsmusicservicesnl@web021.prod.widos.net
Could not execute: /usr/sbin/sendmail -t -i -f jochemsmusicservicesnl@web021.prod.widos.net

I haven't touched the mail settings in any way.
Using V5, build 1999,
Anyone knows the solution?

Thanks, Pieter

Found the solution! Seems I forgot to re-upload the proper 'user.cfg.php' settings' .
cheers, Pieter

Hi Pieter,

The error suggests that PHPMailer is trying to use the server's sendmail function, but the hosting provider has disabled the `popen()` function for security reasons. Since you haven't changed your mail settings, it's possible that your hosting provider recently updated their server configuration.

A few things to check:

* Verify whether your hosting provider has made any recent changes to PHP security settings.
* Switch the form mailer from Sendmail to SMTP if that option is available in your form settings.
* Confirm that your SMTP server, username, password, and port settings are correct.
* If the issue started immediately after updating the software, check whether there is a newer build or patch available.

You may also want to contact your host and ask whether `sendmail` or `popen()` has been disabled recently, as the error points directly to a server-side restriction rather than a problem with your form configuration.

Hope this helps!