Error in Discovery of one divice

When I run the discovery of one divice I get the error
Warning: Cannot use a scalar value as an array in /opt/librenms/includes/rewrites.php on line
(different lines)

This results that the rrd stats stopped filling.
On the other diveces I monitor also (PFSENSE) this is no problem.

Can any one point me to the richt solution after 5 day’s i’m running out of a solution.