Autopilot Wont't Fly Flight Plan

[jmhelms 20]

Somethings happened to my sim...the autopilot will not

accurately fly a predetermined flight plan (made by someone else)...

it is 10-15 degrees off...it could be the plane I'm using, but all the

planes I've tried do the same thing...otherwise the autopilot works

well...the problem even manifests itself when using one of my 

two autopilot external applications..... for clarification

purposes, its when I'm using the "Nav" function...

[Bdub22 1,616]

We're gonna need a lot more info. What plane are you using. What is the flight plan. What external auto pilot applications are you using. It's going to be almost impossible to identify the issue with the amount of information you've shared. 

[rick celik 1,245]

As mentioned above, more info. What addons are you using?

[JYW 2,989]

3 hours ago, jmhelms said:

Somethings happened to my sim...the autopilot will not

accurately fly a predetermined flight plan (made by someone else)...

it is 10-15 degrees off...it could be the plane I'm using, but all the

planes I've tried do the same thing...otherwise the autopilot works

well...the problem even manifests itself when using one of my 

two autopilot external applications..... for clarification

purposes, its when I'm using the "Nav" function...

It's not just a heavy crosswind is it, making it look like you're autopilot is flying 10-15 degrees off, because the track is so far off from the heading?

Eg.

Edited April 14 by JYW

[jmhelms 20]

I think (maby) I have solved the problem...the problem

is an incompatible addon...let me do some more research and 

report back...thanks to all who responded...