problem sending campaign

HI, I am a new SuiteCRM user and I tried to built a campaign, which was perfectly done, however the system doesn´t send the campain to Contacts, and I do not know the reason. When I checked Status, in Targets, I saw the problema is as below:
Warning: Invalid argument supplied for foreach() in /home4/wealcli/public_html/ on line 453.

Somente can help me please?