docedoc123

Thanks, for the tip. I had looked at your post and wondered whether it could be a starting point. I’ll study your code a bit and then maybe I’ll know enough to ask questions.

Interesting. Only change I made was updating the plugin. But it is a shared host and WebHosting Hub may have made changes to the server along the way. In retrospect I should have tested whether the error persisted prior to the update. But . . .

By the way, updating to the latest version (Constant Contact Forms for WordPress 1.84) did not cause errors. So whatever changed appears to have persisted.

Updating the plugin appears to have resolved the issue.

The updated Constant Contact Forms for WordPress Version 1.8.3 plugin on Word Press version 5.4.1 does not crash site on plugin activation.

Thanks for publishing the update if that was actually the solution. Alternatively, might Constant Contact have made other changes that affected the results?

Alas, it happened again. Here is the error detail from public_html/wp-content/debug-log

[11-May-2020 21:08:47 UTC] PHP Fatal error: Illegal length modifier specified ‘f’ in s[np]printf call in /home/custo451/public_html/wp-content/plugins/constant-contact-forms/vendor/guzzlehttp/streams/src/StreamInterface.php on line 7

[11-May-2020 21:10:20 UTC] PHP Fatal error: Illegal length modifier specified ‘f’ in s[np]printf call in /home/custo451/public_html/wp-content/plugins/constant-contact-forms/vendor/guzzlehttp/streams/src/StreamInterface.php on line 7

WordPress reports:
When seeking help with this issue, you may be asked for some of the following information:
WordPress version 5.4.1
Current theme: Avada Child (version 1.0.0)
Current plugin: Constant Contact Forms for WordPress (version 1.8.2)
PHP version 7.3.11

I activated the production domain customercare[dot]com plugin (briefly) at 17:11 today to generate the fatal error. Perhaps that event will show up in your logs.

At the time of the original post

Production domain customercare[dot]com, plugin activation causes error
Staging domain: stage[dot]customercare[dot]com/stage, plugin activation no error

As of 11-May 06:50 EDT cci[dot]customercare[dot]com is the domain to which the production domain is redirected as a work around. Activating the plugin in this subdomain works.

If you need the production domain’s plugin activated to recreate the error, let me know.

As a workaround I redirected traffic from the domain I need help with to a subdomain in which the plugin works.

I am guessing that when the plugin is in the domain (rather than subdomain) it interacts with Constant Contact on activation. The response from Constant Contact contains an illegal length modifier. When the plugin is in any subdomain it receives a different response?

So far as I can determine, the only plugin that uses guzzlehttp is Constant Contact Forms for WordPress.