I have never declared a variable of the fixed type. I mainly have always used var ...
That's a paradoxon.

"var" is just a synonym for "fixed". It's the same 22.10 fixed point type. If you have a look into acknex.h you will find the redefinition:
Sorry, didn't want to confuse you. I am just more used to fixed than to var.
"Syntax error:Can't convert MOD:FLOAT:FLOAT:FLOAT"
basically means, that the modulo operator is not defined for floating point numbers.