My guess would be a type mismatch.
DIM test(24) AS INTEGER
...
SUB RADIX_SORT (ARR())
....
RADIX_SORT (test())
Test is an integer array.
Radix_Sort wants an undefined array, which defaults to a SINGLE type. This causes issues.
Second issue: Passing your array inside parentheses.
RADIX_SORT (test())
This can cause issues. Drop those parentheses and just pass it as:
RADIX_SORT test()
Correct the type mismatch, remove the parentheses, and I bet the issue will go away.