Direct Query is not working while Connecting to Oracle database

Getting this error while connecting to Oracle DB in Direct Query Mode

Feedback Type:
Frown (Error)

Timestamp:
2017-12-19T11:47:58.6619634Z

Local Time:
2017-12-19T17:17:58.6619634+05:30

Session ID:
ff5cebf2-e6bf-4c74-a7dd-a468bb9100c9

Release:
October, 2017

Product Version:
2.51.4885.1423 (PBIDesktop) (x64)

Error Message:
Couldn't load the model schema.

OS Version:
Microsoft Windows NT 6.1.7601 Service Pack 1 (x64 en-US)

CLR Version:
4.6.1 or later [Release Number = 394271]

Peak Virtual Memory:
3.64 GB

Private Memory:
272 MB

Peak Working Set:
370 MB

IE Version:
11.0.9600.18837

User ID:
2795a532-5a7b-46f4-83d2-985af37ff228

Workbook Package Info:
1* - en-GB, Query Groups: 0, fastCombine: Disabled, runBackgroundAnalysis: True.

Telemetry Enabled:
True

Model Default Mode:
DirectQuery

Snapshot Trace Logs:
C:\Users\b19220\AppData\Local\Microsoft\Power BI Desktop SSRS\FrownSnapShot1127532580.zip

Performance Trace Logs:
C:\Users\b19220\AppData\Local\Microsoft\Power BI Desktop SSRS\PerformanceTraces.zip

Disabled Preview Features:
PBI_shapeMapVisualEnabled
PBI_EnableReportTheme
PBI_numericSlicerEnabled
PBI_SpanishLinguisticsEnabled
PBI_daxTemplatesEnabled
CustomConnectors
PBI_reportBookmarks

Disabled DirectQuery Options:
PBI_DirectQuery_Unrestricted

Cloud:
GlobalCloud

Couldn't load the schema for the database model:
Couldn't load the model schema associated with this report. Make sure you have a connection to the server, and try again.

Activity ID:
null

Time:
Tue Dec 19 2017 16:22:37 GMT+0530 (India Standard Time)

DPI Scale:
100%

Supported Services:
Power BI Report Server, Power BI

Formulas:

in
Source;