Error messages

I get the following error messages using the plugin.

[14-Dec-2018 21:57:23 UTC] PHP Notice: Use of undefined constant GLOB_BRACE – assumed ‘GLOB_BRACE’ in /mnt/web314/e0/11/579511/htdocs/wp-content/plugins/the-events-calendar-category-colors/src/Category_Colors/Frontend.php on line 116

[14-Dec-2018 21:57:23 UTC] PHP Warning: glob() expects parameter 2 to be long, string given in /mnt/web314/e0/11/579511/htdocs/wp-content/plugins/the-events-calendar-category-colors/src/Category_Colors/Frontend.php on line 116

[14-Dec-2018 21:57:23 UTC] PHP Notice: Use of undefined constant GLOB_BRACE – assumed ‘GLOB_BRACE’ in /mnt/web314/e0/11/579511/htdocs/wp-content/plugins/the-events-calendar-category-colors/src/Category_Colors/Frontend.php on line 140

[14-Dec-2018 21:57:23 UTC] PHP Warning: glob() expects parameter 2 to be long, string given in /mnt/web314/e0/11/579511/htdocs/wp-content/plugins/the-events-calendar-category-colors/src/Category_Colors/Frontend.php on line 140

[14-Dec-2018 21:57:23 UTC] PHP Warning: Invalid argument supplied for foreach() in /mnt/web314/e0/11/579511/htdocs/wp-content/plugins/the-events-calendar-category-colors/src/Category_Colors/Frontend.php on line 140

What might be the reason???