Are semi-frozen meat and vegetables safe to cook?
Sure. What would make them unsafe?  We freeze to preserve food all the time.  More importantly, this freezing will likely impact the quality, especially the vegetables.  I am guessing there is likely some freeze and thaw, which is not good for storage, as the ice crystals damage the cell structure of foods.  However, as long as you cook the chicken properly (to the appropriate internal temperature), there is not a safety issue.  Maybe adjust your refrigerator settings so that this doesn't happen...or store vegetables in an alternate location in your refrigerator.