i need some help about mcdu flight plans , always from simbrief these flight plans are wrong and have discotinuties , so i must set departure and arrival to be correct after i deleting the discotinuing , why always simbrief have this problem and is not only this after some waypoints stop reducing and is not going the next waypoint … ?
I got the same, but only in the Airbus.
Long story short. Review the procedures itself, do not rely on SimBrief. A discontinuity is usually something you need to pay attention to and cannot just summarily delete.
Yes, this applies to SID and STAR procedures that users insert AFTER they have loaded flightplans into their FMS/MCDU.
But what at least I get all the time with flightplans that my FBW A320Neo and Headwind A330-900 (they both share the same code for the FMS/MCDU) load from Simbrief is that there is a discontinuity after the departure airport and another one before the arrival airport. Both can be deleted without hesitation. The MCDU often also generates a discontinuity after the last point of the SID, after selecting and inserting the procedure. This one can be deleted as well. The question is whether this is realistic or not. I don’t mind having to delete those discontinuities, it’s just a minor nuisance.
One situation where the discontinuity exists for a good reason is when you might be making a circling approach. If the discontinuity has been cleared by the time you approach the opposite end of the runway, the FMGS will consider the aircraft to have passed that waypoint and will forget the selected runway. Of course, re-programming the correct runway information into the MCDU just as you’re performing a somewhat challenging visual manoeuvrer across an airport is not ideal 
The exact wording in the Thales FMGS manual is as follows:
Do not clear discontinuity before CF waypoint as this would cause loss of RWY due to leg switching as RWY is passed.
The Airbus Flight Crew Training manual is rather more terse in its instruction:
• Keep the F-PLN discontinuity
But we are not talking about discontinuities that were created when inserting a departure, arrival or approach procedure, but discontinuities that are present after downloading the flightplan on the INIT-page. These are 2 different pairs of shoes.