I just noticed with version 1.8 Revision 21800 that the barcode window is not opened for an object if barcode is set to Code39 in the settings.
The message is comes from apache and says "Forbidden - You don't have permission to access /src/tools/php/barcode_window.php on this server."
You can see this on the test-page at https://demo.i-doit.com/ when
- setting the barcode-type to Code39 and then
- opening an object an clicking on the barcode