Anyone having trouble creating or updating Dropbox / Assignments?

I'm trying to POST to /d2l/api/le/1.25/{ouid}/dropbox/folders/ or PUT to /d2l/api/le/1.25/{ouid}/dropbox/folders/{folderid} without success. My nodejs code and the https://apitesttool.desire2learnvalence.com/ both fail with  { "type": "http://docs.valence.desire2learn.com/res/apiprop.html#invalid-parameters", "title": "Invalid Parameters", "status": 400, "detail": "Request has missing or invalid parameters."} There's no data about what parameter is missing or invalid.  Here's my json body for an example PUT request {   "CategoryId": null,   "Name": "MikesTest Renamed",   "CustomInstructions": {       "Text": "Here are some instructions",       "Html": "

Here are some instructions

"   },   "Availability": null,   "IsHidden": false,   "GroupTypeId": null,   "DueDate": null,   "DisplayInCalendar": false,   "NotificationEmail": null} Any help is greatly appreciated. Thanks!