Fatal error: Unknown: Cannot use output buffering in output buffering display…

  • Resolved aussielats

    (@aussielats)


    4 years, 11 months ago

    I have W3 Total Cache and WP Fastest Cache (whether both are needed is up for debate, currently I do because of W3 issue as below) and when I have W3 activated, it crashes my site with the following error

    Fatal error: Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0

    It might be a simple setting somewhere but this error has only occurred of late so has the author seen this before?

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

Viewing 5 replies - 1 through 5 (of 5 total)
  • Plugin Contributor Marko Vasiljevic

    (@vmarko)

    Hello @aussielats

    I am sorry about the issue you are experiencing and I am happy to help.
    When did this issue start to occur? Using more than one caching solution is not recommended as it can cause a lot of conflicts and similar to the error message you provided.
    Try purging all cache and see if the issue persists. if the issue persists, temporarily deactivate all other plugins and/or switch to the theme and see if the problem goes away?
    If the issue is gone re-enable the other plugins one by one and see which one might be causing the conflict.
    Thank you!

    Thread Starter aussielats

    (@aussielats)

    It is probably in the last week the issue has occurred (even though both W3 and WP have always been running together) and the strange thing is once the error occurs on one page, refresh and the page usually loads, click on another link and the error may or may not occur even if all caches are purged. But guaranteed the error will occur.

    Plugin Contributor Marko Vasiljevic

    (@vmarko)

    Hello,
    This is definitely because of the conflict with the other caching plugin. As previously stated and advised, it is not recommended to use more than once a caching solution. If you want to continue using both caching plugins please understand that you are doing that at your own risk.
    Thank you!

    Thread Starter aussielats

    (@aussielats)

    Forgot to mention earlier that the error happens even when the other cache plugin is disabled.

    Plugin Contributor Marko Vasiljevic

    (@vmarko)

    Hello @aussielats

    Then it’s possible that when another plugin is disabled there is a conflict with remaining drop-ins or other files.

    Try purging all cache and see if the issue persists. if the issue persists, temporarily deactivate all other plugins and/or switch to the theme and see if the problem goes away?
    If the issue is gone re-enable the other plugins one by one and see which one might be causing the conflict.

    This will help you understand where the conflict is.
    Thank you!

Viewing 5 replies - 1 through 5 (of 5 total)
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