Help me in fixing the issue

[seba antony97]

i have 100 records and 27 rules.

Traceback (most recent call last):

  File "C:\Python34\lib\site-packages\skfuzzy\control\controlsystem.py", line 588, in defuzz
    self.var.defuzzify_method)
  File "C:\Python34\lib\site-packages\skfuzzy\defuzzify\defuzz.py", line 248, in defuzz
    assert not zero_truth_degree, 'Total area is zero in defuzzification!'
AssertionError: Total area is zero in defuzzification!

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:/Python34/fis3_nooverlap.py", line 100, in <module>
    mamdani(int(row[2]),int(row[3]),int(row[4]),int(row[5]))
  File "C:/Python34/fis3_nooverlap.py", line 92, in mamdani
    courseH.compute()
  File "C:\Python34\lib\site-packages\skfuzzy\control\controlsystem.py", line 374, in compute
    CrispValueCalculator(consequent, self).defuzz()
  File "C:\Python34\lib\site-packages\skfuzzy\control\controlsystem.py", line 590, in defuzz
    raise ValueError("Crisp output cannot be calculated, likely "
ValueError: Crisp output cannot be calculated, likely because the system is too sparse. Check to make sure this set of input values will activate at least one connected Term in each Antecedent via the current set of Rules.