diff --git a/DXFeedFramework/Native/Graal/Isolate.swift b/DXFeedFramework/Native/Graal/Isolate.swift
index 9f224897d..66ae6ace0 100644
--- a/DXFeedFramework/Native/Graal/Isolate.swift
+++ b/DXFeedFramework/Native/Graal/Isolate.swift
@@ -100,6 +100,7 @@ class Isolate {
 
     func throwException() throws {
         let thread = currentThread()
-        _ = try ErrorCheck.nativeCall(thread, dxfg_throw_exception(thread))        
+        _ = try ErrorCheck.nativeCall(thread, dxfg_get_and_clear_thread_exception_t(thread)) // to init com.dxfeed.sdk.NativeUtils
+        _ = try ErrorCheck.nativeCall(thread, dxfg_throw_exception(thread))
     }
 }
diff --git a/DXFeedFramework/Utils/Optional+Ext.swift b/DXFeedFramework/Utils/Optional+Ext.swift
index 11a6f7151..a24e6b75c 100644
--- a/DXFeedFramework/Utils/Optional+Ext.swift
+++ b/DXFeedFramework/Utils/Optional+Ext.swift
@@ -9,9 +9,11 @@ import Foundation
 
 extension Optional {
     func value() throws -> Wrapped {
-        guard let value = self else {
+        switch self {
+        case .none:
             throw GraalException.nullException
+        case .some(let val):
+            return val
         }
-        return value
     }
 }