You defined owner of the loaded xib as nil. Since file owner in xib itself has outlets connected and is defined as instance of ShareView you get the exception about unknown keys (nil doesn't have outleted properties you defined for ShareView).
You should define the loader of the xib as owner (i.e. view controller responsible for loading the xib). Then add separate UIView object to xib and define it as instance of ShareView. Then when loading the xib.
ShareView *shareView = [[[[NSBundle mainBundle] loadNibNamed:@"ShareView" owner:self options:nil] objectAtIndex:0] retain];
You can also define shareView as an IBOutlet in view controller's interface (and connect the outlet from file owner to that view in the xib itself). Then when you load the xib there won't be any need for reassigning the shareView instance variable since the xib loading process will reconnect the view to the instance variable directly.