Export function crashes Unity editor 2019.4 LTS

AssimpContext exporter = new AssimpContext();
exporter.ExportFile(scene, "savePath", "objnomtl");
ExportDataBlob blob = exporter.ExportToBlob(scene, "objnomtl");

both these methods crash Unity no matter how I try and save these in the Unity Editor (saving to StreamingAssets).
writing bytes with streamwriter and with File.Create() both fail, although I think the issue is with the implementation in the DLL.

How does the unmanaged DLL try to save the files? Can the wrapper be written differently to save the file the way you would in Unity.