Creation of new Custom Object Instances in New UX is not possible if you have an attachment attribute and it's a Required field
STEPS TO REPRODUCE:
1. Login To Clarity.
2. Create a new Custom Object, Test Object which is API enabled.
3. Create a new attribute of type attachment on the new custom object, add an API alias and make it value required.
4. Add all custom object rights to the user.
5. Login to new ux and navigate to custom objects.
6. Create a new instance, Add the Name, ID and browse a file in the attachment attribute.
Expected Results :- The instance gets created successfully.
Actual Results :- Instance creation fails with API-1019 : Could not process the request due to internal error.
Release : 15.9.3
Component : Clarity MUX Custom Objects and Custom Investments
This is caused by defect DE62554 and is under engineering review.
Workaround :- Change the attachment attribute from Required to Not Required.