uexplained Stack: IF(line nmber) error at compilation time

SmallBASIC implementations: 

Hi everyone,

I had an old Smallbasic program, initally written under Powerbasic, then adapted to Smallbasic under Windows in 2005, and that now needs to be re-activated under Ubuntu Linux.
Apart from some minor changes in syntax, things seemed to work well, until during the debugging Smallbasic started
complaining at the time of compilation with an error of the kind "Stack: IF(line number)" that I can't find the reason for.

The statement itself is correct, and is in one of several identical repeating blocks of commands that are not frowned at by the compiler, and it looks to me like I run over some limits or run out of resources of some kind.

I can't find any help for this in the help files.
I wonder if I need to reserve memory or other resources, or start with some DIM commands (which seem not to exist in Smallbasic anyway)

Can anyone help me finding help?

I tried to "inject" my code into Gambas 3, but I just started with that language, and never used Visualbasic, and the way to some successful programming seems way longer than the one through Smallbasic, while I need a "quick (not dirty) solution.
The Smallbasic program is supposed to re-format some bank records for my accounting program before import, so that is in short: read a csv file, re-format fields, add standard accounting operation lines depending on what the bank movements are, and output the result as another csv file.

Thanks in advance for any hint or help.

You get that kind of error when you have syntax problems with your code. (It seems to be a kind of "generic" error message.)

Can you post the file which causes the error? That might help identifying the problem.