Our company upgraded TD from 14 to 15.2 last weekend. After that, the following error occurred when a translation coordinator tried to register a translation job:

The requestBody field is required. The JSON value could not be converted to System.Nullable`1[System.DateTime]. Path: $.value | LineNumber: 0 | BytePositionInLine: 109.

According to the error message, I suspected that the 'Regional date format' setting was required before creating a translation job for the first time. Actually, after setting the 'Regional date format', the translation job was created without any errors.
I'd like to improve this behavior. In the Organize Space GUI, the default 'Regional date format' has been set. Therefore, the operation should be carried out without any errors.