Error in the template htm /usr/local/ispconfig/interface/web/client/templates/reseller_edit_limits.htm

Line 11 <legend>Limits</legend>

Change to

<legend><tmpl_var name="Limits"></legend>

Add string $wb['Limits'] = 'Limits';

to files translates /usr/local/ispconfig/interface/web/client/lib/lang/{lang}_reseller.lng