(...) but if I have a good memory legacy version isn't developed anymore.
This isn't, true (unfortunately, imo). Legacy version of soldat, aka compiled with delphi&cross kylix verion of soldat will stay as long as client isn't ported to FPC. Which doesn't seem to be moving by much recently, so i guess support for legacy version is going to last long.
Nevertheless, this particular bug is somewhere in pascalscript library, i'm afraid that tracing&fixing it might be quite some work to do. So don't expect it to be fixed soon, even if that means that scripting on legacy server is pretty much impossible.