This behavior also occurred on 1.8.2 for me but only in my local testing environment. Verifying that updating to 1.8.3 fixed the issue. For what it’s worth, here’s the PHP stack trace I was getting:
[17-Feb-2021 16:50:15 UTC] PHP Warning: require(C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\composer/../nicolaskulka/wp-dismissible-notices-handler/handler.php): failed to open stream: No such file or directory in C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\composer\autoload_real.php on line 71
[17-Feb-2021 16:50:15 UTC] PHP Stack trace:
[17-Feb-2021 16:50:15 UTC] PHP 1. {main}() C:\Users\lcraft\Local Sites\localjwcc\app\public\index.php:0
[17-Feb-2021 16:50:15 UTC] PHP 2. require() C:\Users\lcraft\Local Sites\localjwcc\app\public\index.php:17
[17-Feb-2021 16:50:15 UTC] PHP 3. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-blog-header.php:13
[17-Feb-2021 16:50:15 UTC] PHP 4. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-load.php:37
[17-Feb-2021 16:50:15 UTC] PHP 5. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-config.php:77
[17-Feb-2021 16:50:15 UTC] PHP 6. include_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-settings.php:388
[17-Feb-2021 16:50:15 UTC] PHP 7. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\wps-hide-login.php:31
[17-Feb-2021 16:50:15 UTC] PHP 8. require() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\autoload.php:204
[17-Feb-2021 16:50:15 UTC] PHP 9. ComposerAutoloaderInit393b2abbc4f40fa5ed9a0e7160b5b801::getLoader() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\autoload.php:7
[17-Feb-2021 16:50:15 UTC] PHP 10. composerRequire393b2abbc4f40fa5ed9a0e7160b5b801() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\composer\autoload_real.php:61
[17-Feb-2021 16:50:15 UTC] PHP Fatal error: require(): Failed opening required ‘C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\composer/../nicolaskulka/wp-dismissible-notices-handler/handler.php’ (include_path=’.:/usr/share/php:/www/wp-content/pear’) in C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\composer\autoload_real.php on line 71
[17-Feb-2021 16:50:15 UTC] PHP Stack trace:
[17-Feb-2021 16:50:15 UTC] PHP 1. {main}() C:\Users\lcraft\Local Sites\localjwcc\app\public\index.php:0
[17-Feb-2021 16:50:15 UTC] PHP 2. require() C:\Users\lcraft\Local Sites\localjwcc\app\public\index.php:17
[17-Feb-2021 16:50:15 UTC] PHP 3. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-blog-header.php:13
[17-Feb-2021 16:50:15 UTC] PHP 4. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-load.php:37
[17-Feb-2021 16:50:15 UTC] PHP 5. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-config.php:77
[17-Feb-2021 16:50:15 UTC] PHP 6. include_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-settings.php:388
[17-Feb-2021 16:50:15 UTC] PHP 7. require_once() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\wps-hide-login.php:31
[17-Feb-2021 16:50:15 UTC] PHP 8. require() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\autoload.php:204
[17-Feb-2021 16:50:15 UTC] PHP 9. ComposerAutoloaderInit393b2abbc4f40fa5ed9a0e7160b5b801::getLoader() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\autoload.php:7
[17-Feb-2021 16:50:15 UTC] PHP 10. composerRequire393b2abbc4f40fa5ed9a0e7160b5b801() C:\Users\lcraft\Local Sites\localjwcc\app\public\wp-content\plugins\wps-hide-login\vendor\composer\autoload_real.php:61