R crashing during evaluation

Question

I have a .Net winforms application built using 4.8 .Net fwk. It is using R.Net(1.9.0) which is running R engine version 3.5.3.

Recently we started encountering application crashing issue intermittently but quite often also there is no exception is thrown as well. Here is my code for R.Net

REngine.SetEnvironmentVariables();
REngine engine = REngine.GetInstance();
var str = engine.CreateCharacter(...);
engine.SetSymbol("rPath", ...);

engine.Evaluate("setwd(...)");
engine.Evaluate("source(...)");
engine = null;

Any help is appreciated.

Thanks Manish

Tried running this code both synchronously having my engine as static and asynchronously as well but no luck.