CAAML v6 (& v5) needs an integer value for caaml:position
Steps to reproduce the problem: EITHER: Do not enter a value for either slope or aspect angle (n/a for the latter works) OR: enter a value with one decimal, even like 0.0
Expected result: file would validate
Actual result: doesn't
Note: niViz may keep the decimal value, render it, and output it to JSON, no problems; simply CAAML (once more) doesn't digest it.