FRO is Family Responsiblity Office - child support obligations. If your husband is in default of court ordered payments for child support, he will have to pay off any arrears owed, and start making on time payments before he is eligible to sponsor.
From the
Sponsor's Guide, page 9 of 34 (applicable portions):
"
You are not eligible to sponsor if you are in default of a previous sponsorship undertaking, of an immigration loan,
of court ordered support payment obligations, or of a performance bond (an amount you agreed to pay as a guarantee of performance of an obligation under the immigration legislation);
- - - -
Default of any court ordered support payment obligations means you were ordered by a court to make support payments to your spouse, common-law partner or child and have neglected to do so.
- - - -
If you are in default of a previous sponsorship, of an immigration loan,
of court ordered support payment obligations or of a performance bond
and you submit an application to sponsor, it will be refused even if you are sponsoring your spouse, common-law partner, conjugal partner, or child.
Should you want to sponsor again (or successfully in the first place [my note]), you will have to
•
resolve the family support matter to the satisfaction of the provincial or territorial authorities who ordered the payment
(and if your sponsorship was already refused [my note again], you'll have to
• submit a new sponsorship application;
• pay new processing fees; and
• meet all the eligibility requirements for sponsorship at that time."