Hi everyone My problem is when I try to reload or reset or start new scenario with pmdg 737 chosen aircraft my sim(P3Dv4)crashes.i reinstalled pmdg but didn't work.thanks guys  

I don't have much addons only uk2000 Heathrow. 

4 minutes ago, farid822 said:

when I try to reload or reset or start new scenario

Welcome to the forum. Please note that full names - first and last - are required here in the forum.

As far as the issue goes, as noted in the Intro Manual, reloading an aircraft within the same sim session can cause issues. Additionally, do not set the NGX as the default aircraft in the sim, as this has the same effect of re-loading the aircraft within a sim session.

Scandinavian

7 minutes ago, scandinavian13 said:

Welcome to the forum. Please note that full names - first and last - are required here in the forum.

As far as the issue goes, as noted in the Intro Manual, reloading an aircraft within the same sim session can cause issues. Additionally, do not set the NGX as the default aircraft in the sim, as this has the same effect of re-loading the aircraft within a sim session.

Farid Zeynalov. Thanks for reply. I didn't set pmdg 737 I just downloaded and that is it.Maybe it's done on its own. How not to set it default aircraft in the sim? 

Please explain me simplest way u can. Thanks. 

2 hours ago, farid822 said:

I didn't set pmdg 737 I just downloaded and that is it.Maybe it's done on its own.

The PMDG installer will not set the default flag, that is illogical because PMDG does not want you to set it.

Make sure the Select Scenario window is what opens when you start P3D,  click the Show on Startup box on that window.  The default airplane is the one in the spinning preview window before you select an airplane or scenario.  If you want to reload, reset or start a new scenario you have to quit P3D and start a new session. This is explained in the Introduction and this is exactly the same thing Kyle told you, he did not say you had selected default,  he did say don't do that.