Cannot read field "result" because "fi" is null, Once more

[MWdal]

Running transformation scenario DITA Map Webhelp Responsive gives Nullpointerexception Cannot read field "result" because "fi" is null. Oxygen version 24.0, DITA OT version 3.6.1.
I saw some old posts on this subject, and based on those I checked that we don't have any file names with square brackets AND apostrophes. So there must be something else that triggers this exception.
One post reply said that the problem with brackets and apostrophes was fixed in DITA OT 3.7, not sure if our particular problem is also fixed in 3.7. We have quite a long process for upgrading to a later version, so all tips, outside of upgrade, are much appreciated. Our workaround now is to temporarily go back to version 21.0 of Oxygen, where we don't get this error, for each transformation.
thanks, Mikael

[Costin]

Hi Mikael,

As you mentioned you are currently using the veersion 24.0 of Oxygen, which comes with DITA OT 3.6.1 and, as you also figured out, some DITA Open Toolkit issues were fixed in the newer version 3.7 (which is the officially supported DITA OT with the minor version 24.1 of Oxygen), the first thing you should try would be to download and install the latest version of Oxygen software available on our website and use it with the DITA OT 3.7, then try running the WebHelp transformation scenario and see if the issues still occur.

If you still encounter issues, even when using the latest version of Oxygen and the DITA-OT 3.7, to investigate further, we need you to sent us (either directly, on support@oxygenxml.com) or through the online support form on our website, a complete DITA Map files hierarchy, in an as minimal form as possible, that we could use to reproduce the issues, along with a description of the issues you encountered.

Regards,
Costin