Using xHarbour.com's xBuild compiler, I was getting "Error E0030 Syntax error at '7'". It occurred at a FIELD declaration line, and I determined that '7' had nothing to do with it. The problem was that one of the fields listed had the name "IDNO" all in caps. As soon as I changed it to "IDno" - mixed case - then the problem went away. There was no variable declaration in any .ch files going into the preprocessor that conflicted to account for this. So it seems there can be case sensitivity and maybe some "magic words" that can cause problems.
Anyway, I'm just suggesting that if you get this E0030 error on some variable that is stated all in upper case, you could try changing the case from upper to lower of some characters to see if that will work. It worked for me. Don't know why.