Json To Features ERROR 001558: Error parsing json file. The workspace is not connected

I am trying to convert a JSON file into a feature. My code was working fine until today and now I am getting the following error – ExecuteError: ERROR 001558: Error parsing json file '<filepath>'. The workspace is not connected..

I tried it manually in ArcMap using this proceedure:

• I first checked that the JSON file looked correct (had all the prerequisites like geometryType, Features, etc…).
• In arcMap (10.5), I went to toolbox > Conversion Tools > JSON > JSON To Features.
• I input the filepath to the .json file and then made sure the output went to a .gdb.
• I double checked the filepaths.

Same results: ERROR 001558. I even tried the default output, which went to the ArcGISDefault.gdb. I also got the same error:

ExecuteError: ERROR 001558: Error parsing json file ”. The
workspace is not connected. Failed to execute (JSONToFeatures).

In researching this issue, I found the ArcGIS Pro page on 001558: Error parsing .json file <value> which states that the The JSON must have at least the geometryType, spatialReference, fields, and features (with geometry and attributes) property. I checked the data and it has
geometryType, spatialReference, fields, and features which have attributes and geometry.

{"displayFieldName": "CSLF_ID",
"fieldAliases": {...},
"geometryType": "esriGeometryPolygon",
"spatialReference": {
  "wkid": 102100,
  "latestWkid": 3857
},
"fields": [...],
"features": [
  {"attributes": {...},
   "geometry": {...}
  },...]}

So, I am wondering if there might be something else causing the error. Or can anyone see an issue with the JSON file above?