I'm work with version as below:
Oracle.ManagedDataAccess: 21.16.0
Oracle.ManagedDataAccess.EntityFramework: 21.9.0
EntityFramework: 6.4.4
But, the error happen when I try to:
- Update model with error message:

2. or update model with error message: 
3. Create new model with error message:

4. or create new model with error message:

5. Can't load model:

Please help me to give an advise on these case error, i try to fix but i can't fix it successful.
Thank you so much!
Mrs. Huyen