[Lazarus] TThread.Synchronize

[LacaK]

>> I do not call CheckSynchronize nor ProcessMessages in my application.
>> So only any LCL component or widget set can call it in background ?
>
> It should be easy for you to set a breakpoint into MyForm.MyMethod and 
> check the call stack.
>
But error (AV) happens only in production and only sometimes.
Is there any way how to write call stack into file ?
TIA
-Laco.