Title: PHP 8.0 compatibility error Last modified: September 27, 2022 --- # PHP 8.0 compatibility error * Resolved [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/) * The following ended up in my debug.log: * > PHP Deprecated: Invalid characters passed for attempted conversion, these have > been ignored in /home/redacted/public_html/wp-content/plugins/amp/src/ReaderThemeSupportFeatures. > php on line 375 Viewing 15 replies - 1 through 15 (of 20 total) 1 [2](https://wordpress.org/support/topic/php-8-0-compatibility-error/page/2/?output_format=md) [→](https://wordpress.org/support/topic/php-8-0-compatibility-error/page/2/?output_format=md) * Plugin Support [Milind More](https://wordpress.org/support/users/milindmore22/) * (@milindmore22) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16051295) * Hello [@bozzmedia](https://wordpress.org/support/users/bozzmedia/) * Thank you for contacting us, I think you also faced [similar issue](https://wordpress.org/support/topic/php-deprecated-invalid-characters-passed-for-attempted-conversion-4/) when you are using PHP 7.4.0 so I doubt that this is related to the PHP version, the issue might be related to your hex color code. * To make sure we also tested it with PHP 8.0.21 and we didn’t get any warning. * To debug the issue further Can you please log in as Admin and visit Appearance- > AMP -> Colors & Dark Mode, Copy the color code and send it back to us by replying to this thread * I hope this helps! * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16052426) * Thank you [@milindmore22](https://wordpress.org/support/users/milindmore22/) for your help here and in my other thread that I completely forgot about (sorry!). * I am using Reader Mode with the AMP Legacy theme. I checked the color settings and the only thing that I noticed was for one color I was using an abbreviated hex code `#fff`. While I figure that is still a compliant syntax I changed it to `#ffffff` — let’s see if that does the trick. * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16052760) * So far, no impact. More lines of the error here indicating it may be several items? * ``` [28-Sep-2022 19:34:21 UTC] PHP Deprecated: Invalid characters passed for attempted conversion, these have been ignored in /home/redacted/public_html/wp-content/plugins/amp/src/ReaderThemeSupportFeatures.php on line 375 [28-Sep-2022 19:34:21 UTC] PHP Deprecated: Invalid characters passed for attempted conversion, these have been ignored in /home/redacted/public_html/wp-content/plugins/amp/src/ReaderThemeSupportFeatures.php on line 376 [28-Sep-2022 19:34:21 UTC] PHP Deprecated: Invalid characters passed for attempted conversion, these have been ignored in /home/redacted/public_html/wp-content/plugins/amp/src/ReaderThemeSupportFeatures.php on line 377 ``` * Plugin Support [Milind More](https://wordpress.org/support/users/milindmore22/) * (@milindmore22) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16054987) * Hello [@bozzmedia](https://wordpress.org/support/users/bozzmedia/) * Can you please send your site health information using [this form](https://forms.gle/gJL8MZXHGsAFFaBYA) so we can try to re-create your site environment and debug the issue * Plugin Author [Weston Ruter](https://wordpress.org/support/users/westonruter/) * (@westonruter) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16055958) * This is the code in question: [https://github.com/ampproject/amp-wp/blob/a373ac8f65f26ee7df7313ff5d734b5704781ab0/src/ReaderThemeSupportFeatures.php#L366-L380](https://github.com/ampproject/amp-wp/blob/a373ac8f65f26ee7df7313ff5d734b5704781ab0/src/ReaderThemeSupportFeatures.php#L366-L380) * The code being complained about is: * ``` $red = hexdec( substr( $hex, 0, 2 ) ); $green = hexdec( substr( $hex, 2, 2 ) ); $blue = hexdec( substr( $hex, 4, 2 ) ); ``` * No error occurs when `$hex` is `ffffff`: [https://3v4l.org/VTmvu](https://3v4l.org/VTmvu) * However, if `$hex` is `#ffffff` then the reported issue occurs: [https://3v4l.org/RNVnF](https://3v4l.org/RNVnF) * Nevertheless, this `#` should not be present because of [this code](https://github.com/ampproject/amp-wp/blob/a373ac8f65f26ee7df7313ff5d734b5704781ab0/src/ReaderThemeSupportFeatures.php#L366-L367): * ``` // Remove the "#" symbol from the beginning of the color. $hex = ltrim( $hex, '#' ); ``` * So what specifically is `$hex` for you as being passed into your `get_relative_luminance_from_hex` method? - This reply was modified 3 years, 8 months ago by [Weston Ruter](https://wordpress.org/support/users/westonruter/). * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16065994) * I have hex codes complete with the # symbol in the Customizer > AMP settings. * I will see if removing those helps. Thanks for the insight! * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066170) * OK, I went to run through this again and instead of manually pasting in the hex code I used the color picker. It adds the # symbol to the field automatically. * I’m not sure how to debug what the actual $hex values are, but happy to try if you can point me in the right direction. Thanks again. * Plugin Author [Weston Ruter](https://wordpress.org/support/users/westonruter/) * (@westonruter) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066455) * I still don’t see how including or omitting the `#` would make any difference because the code is doing `ltrim( $hex, '#' )`, which means any initial `#` will be stripped. * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066468) * Here is the frontend html from the customizer, does this help? Let me know how else I can help debug. * ``` ``` * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066472) * Color Codes: #ffffff #f16202 * I sent in the form with other system info. Thanks! - This reply was modified 3 years, 8 months ago by [Marty](https://wordpress.org/support/users/bozzmedia/). * Plugin Author [Weston Ruter](https://wordpress.org/support/users/westonruter/) * (@westonruter) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066509) * What may be helpful is if you can edit the source code of this method: * [https://github.com/ampproject/amp-wp/blob/a373ac8f65f26ee7df7313ff5d734b5704781ab0/src/ReaderThemeSupportFeatures.php#L364-L382](https://github.com/ampproject/amp-wp/blob/a373ac8f65f26ee7df7313ff5d734b5704781ab0/src/ReaderThemeSupportFeatures.php#L364-L382) * Before these lines: * ``` // Get red, green, blue. $red = hexdec( substr( $hex, 0, 2 ) ); $green = hexdec( substr( $hex, 2, 2 ) ); $blue = hexdec( substr( $hex, 4, 2 ) ); ``` * Add this: * `error_log( '$hex === ' . json_encode( $hex ) );` * Then trigger whatever you do to cause the deprecation notice, and then open the error log to look for that log entry. You may need to [enable](https://wordpress.org/support/article/debugging-in-wordpress/#wp_debug_log)` WP_DEBUG_LOG`. * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066535) * Done. This popped up: * `Uncaught exception 'ParseError' with message 'syntax error, unexpected token"&"' in /home/redacted/public_html/wp-content/plugins/amp/src/ReaderThemeSupportFeatures. php:374` * Plugin Author [Weston Ruter](https://wordpress.org/support/users/westonruter/) * (@westonruter) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066576) * Er, that’s not expected. Copy/paste error? * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066593) * Here’s what I have: * ``` error_log( '$hex === ' . json_encode( $hex ) ); // Get red, green, blue. $red = hexdec( substr( $hex, 0, 2 ) ); $green = hexdec( substr( $hex, 2, 2 ) ); $blue = hexdec( substr( $hex, 4, 2 ) ); ``` * Thread Starter [Marty](https://wordpress.org/support/users/bozzmedia/) * (@bozzmedia) * [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/#post-16066595) * Here’s the line from debug: * `[04-Oct-2022 00:37:28 UTC] $hex === "var(--base-2)"` * Possibly set from the theme, GeneratePress? Viewing 15 replies - 1 through 15 (of 20 total) 1 [2](https://wordpress.org/support/topic/php-8-0-compatibility-error/page/2/?output_format=md) [→](https://wordpress.org/support/topic/php-8-0-compatibility-error/page/2/?output_format=md) The topic ‘PHP 8.0 compatibility error’ is closed to new replies. * ![](https://ps.w.org/amp/assets/icon.svg?rev=2527602) * [AMP](https://wordpress.org/plugins/amp/) * [Frequently Asked Questions](https://wordpress.org/plugins/amp/#faq) * [Support Threads](https://wordpress.org/support/plugin/amp/) * [Active Topics](https://wordpress.org/support/plugin/amp/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/amp/unresolved/) * [Reviews](https://wordpress.org/support/plugin/amp/reviews/) * 20 replies * 3 participants * Last reply from: [Marty](https://wordpress.org/support/users/bozzmedia/) * Last activity: [3 years, 8 months ago](https://wordpress.org/support/topic/php-8-0-compatibility-error/page/2/#post-16069566) * Status: resolved