Can't add domain or modify IP-Pool of a customer

[Moore]

Hello,

when I'm trying to modify the IP-Pool of a special customer I got the following error:

0: /usr/local/psa/admin/plib/class.IPPoolList.php:120 psaerror(string "Unable to create IP Address object: Table->select() failed: no such row in the table")
1: /usr/local/psa/admin/plib/class.cList.php3:94 ipPoolList->fetchIPPoolList()
2: /usr/local/psa/admin/plib/class.cList.php3:114 ipPoolList->fetchList()
3: /usr/local/psa/admin/htdocs/clients/cl_pool.php3:84 ipPoolList->init()

And when I try to add a domain to the same special customer I got:

0: /usr/local/psa/admin/plib/class.CreateDomainForm.php:100 psaerror(string "Unable to create IP Address object: Table->select() failed: no such row in the table")
1: /usr/local/psa/admin/htdocs/domains/create_domain.php:246 CreateDomainForm->assign(string "true", string "", object of type Client, object of type IPPool, string "true", object of type BsDomain, boolean false)

I have other customers on the same machine and there I can do it without problems. I'm using Plesk reloaded 7.5.4.

Please give advise to solve the problem.

Regards,
Moore