outlook.com calendar error

I have an outlook.com account and it is being synchronized with 2 apps. One is in my cell phone and the other is em client. When I am adding a new event in my phones app calendar, It is not being synchronized with em client and I am also getting the message: Invalid reply format(no collection).

Hi Panagiotis,
can you take a screenshot of the error message?
Also, if you make the event in phone, does it appear correctly on the server if you check it online?
Do eM Client events appear correctly in this phone app?

Best regards,
Olivia