What causes the failure of the randomization process?

In reply to UVM_LOVE:

What makes you think that the randomize() call failed? You are using signed 32-bit integers. If you add all the numbers and account for overflow, you will get a value between 0 and 100.

If you want each number to be between 0 and 100, you should add another constraint, although it is impossible to get 100 unique integers between 0 and 100 to sum to a total between 0 and 100.