Bad receiver type 'NSMutableArray *__strong *' error

I'm trying to add an object to an NSMutableArray:

[eyelidDiagnosis addObject: self.labelDescriptions[biggestBlob.getLabel()]];

I'm getting this error on the the line above:

Bad receiver type 'NSMutableArray *__strong *'

This is the declaration of the array:

NSMutableArray *eyelidDiagnosis[5];

How can I go about fixing this?