Hi,
Thanks for your reply! I thought I had looked in the error logs via SFTP directly on my hosted website, but apparantly my ISP shows a different errorlog in their control desk. So thanks for your remark, it made me check again via a different route.
It shows two errors:
FastCGI: server “/var/run/php71-cgi/php-cgi” stderr: PHP message: PHP Warning: mkdir(): Permission denied in /www/wp-content/plugins/participants-database/participants-database.php on line 3270, referer: https://www.*******.nl/?page_id=81
6 Oct. 21:45
AH00529: /sites/*****.nl/www/wp-content/uploads/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable and that ‘/sites/******.nl/www/wp-content/uploads/’ is executable, referer: https://*******.nl/
Im diving into this rights issue now, thanks again!