Ошибка

[SIGPLUS_EXCEPTION_CASE_MISMATCH] Image source корень/images/events_images\slider_21.06.2019 cannot be found with a case-sensitive search but a file system entry корень/images/events_images/slider_21.06.2019 exists. While some operating systems (e.g. Windows) are case-insensitive, others (e.g. Linux) are case-sensitive in matching file system entries. On this server, the image source must match the file system entry exactly, including character case.

[SIGPLUS_EXCEPTION_CASE_MISMATCH] Image source корень/images/events_images\slider_19.06.2019 cannot be found with a case-sensitive search but a file system entry корень/images/events_images/slider_19.06.2019 exists. While some operating systems (e.g. Windows) are case-insensitive, others (e.g. Linux) are case-sensitive in matching file system entries. On this server, the image source must match the file system entry exactly, including character case.

[SIGPLUS_EXCEPTION_SOURCE] Предполагается, что в качестве источника изображения будет полный URL-адрес или путь к базовой папке изображения, указанным в админке, но  events_images/slider_20.02.2019 не является ни URL-адресом, ни относительным путем к существующему файлу или папке.