I have faced such an error during a json import action. Caused by: com.mendix.modules.microflowengine.MicroflowException: Error parsing JSON. Unexpected character ('/' (code 47)): maybe a (non-standard) comment? (not recognized as one since Feature 'ALLOW_COMMENTS' not enabled for parser) at [Source: (org.apache.commons.io.input.AutoCloseInputStream); line: 1, column: 2]
As the message says, it looks like you have a ‘/’ character in the JSON structure. This needs to be escaped with a ‘\’ character.