A PCA is made for reducing the dimensions of data sets through orthogonal (independent) axes of variation, so PC1 must account for a higher variance than PC2, which will be smaller than PC3 and so on..However if you have a data set with lots of zero counts you can have problem when applying the routine HOW for calculating the determinant of the matrix. Is that your case?

Dear Giovanni,

Indeed, thanks for your response, I have re-checked the data and obviously there is an error due to my wrong data entry when i ran the software.

Very true, PC 1 must account for a higher variance than PC 2 and so on. Its good you've confirmed the problem in your data entry.