title: How to solve this error? "property with 'retain(or strong)' attribute must be of object type"
body: <p>I have been working on an app all day which has been working fine until Xcode downloaded libraries or something and then it started having issues. I am just trying to create the getter/setter methods to get a couple of arrays out of my APPDelegate. Like I said it was working fine and then randomly it showed up with this error and now won't build anymore: </p>
  
  <pre><code>property with 'retain(or strong)' attribute must be of object type
  </code></pre>
  
  <p>Here is the rest of the code:</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  #import "Project.h"
  #import "TeamMember.h"
  
  
  @interface Task : NSObject{
  
  NSDate *endDate;
  NSDate *startDate;
  NSMutableString* notes;
  NSMutableString* taskName;
  
  //The error appears first right here over teamMember
  TeamMember *teamMember;
  Project *project;
  
  }
  //The error appears over both of the following lines as well...
  @property  (nonatomic, retain)TeamMember *teamMember;
  @property  (nonatomic, retain) Project * project;
  
  @property (nonatomic, retain) NSMutableString *notes;
  @property (nonatomic, retain) NSMutableString *taskName;
  @property (nonatomic, retain) NSDate *startDate;
  @property (nonatomic, retain) NSDate *endDate;
  
  
  @end
  </code></pre>
  
  <p>Any ideas? This has got me stumped....</p>
  
  <p>Here is Project.h:</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  #import "Task.h"
  
  @interface Project : NSObject{
  
  NSDate *dueDate;
  NSDate *startDate;
  NSArray *tasksInProject;
  NSMutableString* notes;
  NSMutableString* description;
  NSMutableString* projectName; 
  
  }
  @property (nonatomic, retain) NSDate *startDate;
  @property (nonatomic, retain) NSDate *dueDate;
  @property (nonatomic, retain) NSArray *tasksInProject;
  @property (nonatomic, retain) NSMutableString *description;
  @property (nonatomic, retain) NSMutableString *projectName;
  @end
  </code></pre>
  
  <p>Here is TeamMember.h</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  #import "Task.h"
  #import "Project.h"
  
  @interface TeamMember : NSObject{
  
  NSMutableArray *projects;
  NSMutableString *name;
  NSMutableString *title;
  NSMutableString *email;
  NSMutableString *phone;
  NSMutableString *notes;
  }
  
  //@property(nonatomic, retain) NSArray *projects;
  @property (nonatomic, retain) NSMutableString *name;
  @property (nonatomic, retain) NSMutableString *title;
  @property (nonatomic, retain) NSMutableString *email;
  @property (nonatomic, retain) NSMutableString *phone;
  @property (nonatomic, retain) NSMutableString *notes;
  @end
  </code></pre>