ProjectConfig.5.5.php

since a few days I can no longer access my website. I get an error that appears when I make on my site. Here is the error:

Warning: require(/home/MYWEBSITE/admin/config/ProjectConfig.5.5.php): failed to open stream: No such file or directory in /home/MYWEBSITE/admin/config/ProjectConfig.php on line 1

Fatal error: require(): Failed opening required '/home/MYWEBSITE/admin/config/ProjectConfig.5.5.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/MYWEBSITE/admin/config/ProjectConfig.php on line 1

I have made no changes to create it
Can you help me please ?