Thank you for sharing this @Keren Skubach

The SDA to FHIR / FHIR to SDA DTL(which is the primary method we're using for conversion) doesn't support primitive Extension conversion by default. I'll need to implement a custom DTL to achieve this. Alternatively, I can handle it in the code if I generate the FHIR resource programmatically. Can you attach the documentation link for the set resource.property = $listbuild(""original property value",<primitive extension index>,...) primitive extension index set as well. I could see the HS.FHIRModel.R4.Patient from 2024.1 version

Thank you!

When you extend a class with %JSON.Adaptor, you must also ensure that any child classes or classes used as object properties also extend %JSON.Adaptor. Otherwise, you'll encounter an error like:
" ERROR #9411: A class referenced by a %JSONENABLED class must be a subclass of %JSON.Adaptor" during JSON export.

In your case, %DynamicObject/%DynamicArray is a system class that does not extend %JSON.Adaptor, which is why you're unable to export it using methods like %JSONExport, %JSONExportString, or %JSONExportToStream.

To work around this, you can use the Property xAxis As %Library.DynamicObject(%JSONINCLUDE="NONE"); parameter on the problematic field to exclude it from the JSON export.

It depends on your implementation. you can add some conditions like if the date is "00010101" then convert to "1840-12-31" and use that date into $ZDH ($ZDH("1840-12-31",3)) or skip the $ZDH conversion and set 0 directly.