Cookie Size -” Size of a request header field exceeds server limit”

  • I have been receiving this error on my website “
    Bad Request
    Your browser sent a request that this server could not understand.
    Size of a request header field exceeds server limit.”

    After a lot of troubleshooting I found out the problem is related to the cookies generated from your plugin. Even after setting ‘Engagement analytics tracking’ to Partial. the cookies were still being set.

    The above screenshot shows the set-cookie and how it is too large.
    This is the set cookie full text:

    mailpoet_page_view=%7B%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%22timestamp%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%5C%22%3A1725052305%7D; path=/; secure; SameSite=None

    I have disabled the plugin, until you can help me how to fix it. Feel free to contact me if you require any extra information to further fix the issue

Viewing 1 replies (of 1 total)
  • Plugin Support Lynn J.a11n

    (@lynnjat7)

    Hi there @kalashgallery,

    This cookie, for mailpoet_page_view, should be set when a subscriber clicks a link in an email.

    I just tested this out on my test site and the cookie appears to be set correctly. This is what it should look like normally:

    %7B%22timestamp%22%3A1725638833%7D

    If you dig into your cookie, all of this information is there but it is also adding hundreds of backslashes (the %5C character) for unknown reasons.

    Do you know if this error is being seen by all your visitors who click email links, or is it just yours?

    Can you retest this by:

    • clearing all caches and cookie history
    • creating a test email in MailPoet with a link, and sending it to your self
    • clicking the email link, and then checking the loaded cookies on that page to verify the mailpoet_page_view cookie was created properly?

    If not, then please share your system info from under MailPoet > Help on the “system info” tab.

Viewing 1 replies (of 1 total)
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