Silvio,
Get a free copy of WinMerge here: http://winmerge.org/
With that you can compare the FW source code from the working version and the non-working version. This may help you find what is causing the problem.
Another solution may be to use an in-memory temporary DBF instead of an array.
James
FWH 18.05/xHarbour 1.2.3/BCC7/Windows 10