InvalidCastException when instancing generic type

The following code gives me an "InvalidCastException", stating that I can't cast from source to destination type in the foreach loop. I've tried passing multiple different generic collections through the method and I always get this error. I can't figure out why. Any help would be appreciated.

 public static void WriteDataListToFile<T>(T dataList, string folderPath, string fileName) where T : IEnumerable, ICollection
     {    
         //Check to see if file already exists
         if(!File.Exists(folderPath + fileName))
         {
             //if not, create it
             File.Create(folderPath + fileName);
         }
 
         using(StreamWriter sw = new StreamWriter(folderPath + fileName))
         {
             foreach(T type in dataList)
             {
                 sw.WriteLine(type.ToString());
             }
         }
     }

Thanks, Matt