To be more detailed, this is what the error message looks like in the feedback file:

\033[33mWarning:
\033[0m
\033[0m\033[31mError:
\033[0m\033[33mWarning:
\033[0m\033[33mWarning:
\033[0m\033[33mWarning:
cannot calculate average correlation coefficient for file: ’sample4_clean.tsv’
cannot calculate average correlation coefficient for file: ’sample4_clean.tsv’
cannot calculate average correlation coefficient for file: ’sample4_clean.tsv’
cannot calculate average correlation coefficient for file: ’sample4_clean.tsv’
cannot decide the most predictive mean correlation coefficient: ’sample4_clean.tsv’
current predictor is: ’GDP’
current predictor is: ’Homicide Rate’
current predictor is: ’Life Expectancy’
current predictor is: ’Population’
no entity has a valid correlation coefficient in this context
no entity has a valid correlation coefficient in this context
no entity has a valid correlation coefficient in this context
no entity has a valid correlation coefficient in this context
no valid mean correlation coefficient can be calculated from the file

Actually, it means to be:

\033[33mWarning:
cannot calculate average correlation coefficient for file: 'sample4_clean.tsv'
no entity has a valid correlation coefficient in this context
current predictor is: 'Homicide Rate'
\033[0m\033[33mWarning:
cannot calculate average correlation coefficient for file: 'sample4_clean.tsv'
no entity has a valid correlation coefficient in this context
current predictor is: 'GDP'
\033[0m\033[33mWarning:
cannot calculate average correlation coefficient for file: 'sample4_clean.tsv'
no entity has a valid correlation coefficient in this context
current predictor is: 'Population'
\033[0m\033[33mWarning:
cannot calculate average correlation coefficient for file: 'sample4_clean.tsv'
no entity has a valid correlation coefficient in this context
current predictor is: 'Life Expectancy'
\033[0m\033[31mError:
cannot decide the most predictive mean correlation coefficient: 'sample4_clean.tsv'
no valid mean correlation coefficient can be calculated from the file
\033[0m