Whoops, the web server could not write required files to the filesystem.

Running the following commands will fix the issue most of the time:

sudo chown -R librenms:librenms '/opt/librenms'

sudo setfacl -d -m g::rwx /opt/librenms/bootstrap/cache /opt/librenms/storage /opt/librenms/logs /opt/librenms/rrd

sudo chmod -R ug=rwX /opt/librenms/bootstrap/cache /opt/librenms/storage /opt/librenms/logs /opt/librenms/rrd

If using SELinux you may also need:

semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/bootstrap/cache(/.*)?'

semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/storage(/.*)?'

semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/logs(/.*)?'

semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/rrd(/.*)?'

restorecon -RFv /opt/librenms

Check your log for more details. (/opt/librenms/logs/librenms.log)

If that doesn't fix the issue. You can find how to get help at https://docs.librenms.org/Support.