Before applying any changes, make sure to take a backup of the userlib folder. The issue is likely caused by older Jackson JARs (such as jackson-databind, jackson-core, or jackson-annotations) located in userlib, which override the Jackson version expected by OpenAIConnector v7.3.0. Since this older Jackson version does not contain the JsonNode.properties() method, the Java compilation fails. After backing up userlib, remove these Jackson-related JARs, then run Clean Deployment Directory in Studio Pro and start the application again. This will allow Mendix to use its bundled, compatible Jackson version and should resolve the compilation error.
I would suggest reinstalling the dependencies to make sure you have the latest versions of the required modules.
These would be
Once you have done this, go to App->Clean Deployment Directory, then rebuild your app.
Good luck!