Ouch

You can check in the keys.ini file or in the game all the keys so you can change the correct one. Find AcceptCallout and set it to Y if you haven't do

Ho ho. The error message has appeared.
I'm not really sure how this message relates to LSPDFR (I'm not that advanced yet)
But, normally when you see this exception, something is set at <null> when it shouldn't be.
What have you downloaded before the crash?

Have you edited anything prior to the crash?
Delete Immersive Dispatch and see if the issue still persists.
 
PoliceSmartRadio.DisplayHandler..cctor()

I also see this as part of the error.
Do you have PoliceSmartRadio still installed? Or any trace of if left?

FYI it is located at the bottom!
 
There are several issues I noticed with your game. I have outlined them below:
 
Firstly backweapon.dll is a plugin in GTAV/Plugins and it is missing the dll file Agency callouts is now out of date All of Albo11125's plugins are very out of date. These are : Arrest Manager, Police Smart Radio, Albo1125.common Bank callouts is so out of date - one of the oldest out there and the oldest I've seen Crazy Callouts is out of date  Federal callouts is out of date High Priority callouts is out of date LSPDFR+ is out of date OJScenarios is out of date PeterUcallouts is out of date Regular callouts needs an update When I was new to the LSPDFR world I just thought I could install everything I wanted and for it to work. But I too realised this wasn't the case. It is really important to keep your plugins and callouts up to date and if they haven't been updated for 2 versions remove them.
 
All the plugins that I have said are out of date need to be removed as all are considerably out of date. When plugins are no longer supported they will 100% cause crashes and issues such as the one you are experiencing now. They also in general create game stability.
 
I hope I've been helpful and if you have any more issues let me know!
 
 

Check out Beljojo's plugins found here: https://www.bejoijo.com/
It's just worth getting rid of them - I just removed traffic policer and my crashes are almost gone