WP Contact Form Error: ModSecurity PCRE Limits

Resolved dennisporta
(@dennisporta)

11 months, 3 weeks ago
Hi everyone,

I’m facing a recurring issue with my WordPress contact form on STRATO WordPress Basic Hosting. The Problem

My contact form sporadically shows “An error occurred” on submission. Emails are sent, but users don’t get confirmation, leading to duplicate submissions. Form submission is also unusually slow.Crucial Finding from STRATO Server Logs

I checked my STRATO server logs for the last error (June 16, 2025, 13:13 CEST / 11:13 UTC) and found this critical entry:
```
16.06.2025 13:13:06 websitename [client 217.24.96.0] ModSecurity: Rule 254ae00 [id "340157"][file "/opt/RZapache/conf/rules/10_asl_rules.conf"][line "393"] - Execution error - PCRE limits exceeded (-8): (null). [hostname "amadee.de"] [uri "/wp-admin/admin-ajax.php"] [unique_id "aE_8QgyEgxZFYxqcZTkmMAACjQs"]
```
This indicates ModSecurity blocked the form submission because its internal PCRE (regular expression) processing limits were exceeded. This likely happened due to complex or lengthy user input, causing the AJAX request to /wp-admin/admin-ajax.php to fail.My Challenge & Question

STRATO support has informed me they cannot make server-side adjustments to ModSecurity rules or limits for my basic hosting package.

Has anyone experienced similar ModSecurity limit issues on STRATO hosting with contact forms or AJAX requests? What are the possible workarounds or alternative solutions if the host won’t adjust server settings?

Thanks for any help!

The page I need help with: [log in to see the link]

Viewing 2 replies - 1 through 2 (of 2 total)

Plugin Support Nebu John – WPMU DEV Support
(@wpmudevsupport14)

11 months, 3 weeks ago

Hi @dennisporta,

Sorry to know that you are experiencing this issue.

I was unable to observe any similar issues reported from our end. It seems this might be because of an input value from the form, however, you can try switching Submission Method to Page Reload from Ajax and check if that helps.

Please find more about the same in our documentation here: https://wpmudev.com/docs/wpmu-dev-plugins/forminator/#method

Could you please share an export of the form so that we can take a closer look at the issue? Please use Google Drive or Patebin.com to share the export of the form. I hope the following guide comes in handy: https://wpmudev.com/docs/wpmu-dev-plugins/forminator/#import-export

Looking forward to hearing back from you.

Best Regards,
Nebu John

Plugin Support Imran – WPMU DEV Support
(@wpmudev-support9)

11 months, 2 weeks ago

Hello @dennisporta,

I hope you’re doing well.

We haven’t heard from you in a while. I’ll go and mark this thread as resolved. If you have any additional questions or need further assistance, please don’t hesitate to let us know.

–
Kind Regards,
Imran Khan

Viewing 2 replies - 1 through 2 (of 2 total)

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