diff --git a/platform/script-debugger/backend/src/SuspendContextManager.kt b/platform/script-debugger/backend/src/SuspendContextManager.kt
index fb13b95f15f5..a9d1c6413e15 100644
--- a/platform/script-debugger/backend/src/SuspendContextManager.kt
+++ b/platform/script-debugger/backend/src/SuspendContextManager.kt
@@ -68,12 +68,6 @@ enum class StepAction {
    */
   IN,
 
-  /**
-   * Step into first scheduled async handler.
-   * @see <a href="https://groups.google.com/a/chromium.org/forum/#!topic/blink-reviews-bindings/LRAHGXErvOc">Chrome debugger suggestion</a>
-   */
-  IN_ASYNC,
-
   /**
    * Step over the current statement.
    */
diff --git a/platform/script-debugger/debugger-ui/src/DebugProcessImpl.kt b/platform/script-debugger/debugger-ui/src/DebugProcessImpl.kt
index a50e2397a791..8104b203fceb 100644
--- a/platform/script-debugger/debugger-ui/src/DebugProcessImpl.kt
+++ b/platform/script-debugger/debugger-ui/src/DebugProcessImpl.kt
@@ -137,7 +137,7 @@ abstract class DebugProcessImpl<C : VmConnection<*>>(session: XDebugSession,
   override final fun startStepInto(context: XSuspendContext?) {
     val vm = context.vm
     updateLastCallFrame(vm)
-    continueVm(vm, if (vm.captureAsyncStackTraces) StepAction.IN_ASYNC else StepAction.IN)
+    continueVm(vm, StepAction.IN)
   }
 
   override final fun startStepOut(context: XSuspendContext?) {
diff --git a/platform/script-debugger/protocol/protocol-model-generator/src/TypeMap.kt b/platform/script-debugger/protocol/protocol-model-generator/src/TypeMap.kt
index 74e0977c91b0..48834773f002 100644
--- a/platform/script-debugger/protocol/protocol-model-generator/src/TypeMap.kt
+++ b/platform/script-debugger/protocol/protocol-model-generator/src/TypeMap.kt
@@ -18,7 +18,9 @@ internal class TypeMap {
     val domainGenerator = domainGeneratorMap!!.get(domainName)
     if (domainGenerator == null) {
       val qName = "$domainName.$typeName";
-      if (qName == "IO.StreamHandle" || qName == "Security.SecurityState") return BoxableType.ANY_STRING // ignore
+      if (qName == "IO.StreamHandle" || qName == "Security.SecurityState" || qName == "Emulation.ScreenOrientation") {
+        return BoxableType.ANY_STRING // ignore
+      }
       throw RuntimeException("Failed to find domain generator: $domainName for type $typeName")
     }
     return direction.get(getTypeData(domainName, typeName)).resolve(this, domainGenerator)
diff --git a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/OutMessage.kt b/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/OutMessage.kt
index 63a17b083aa4..31f8c204d278 100644
--- a/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/OutMessage.kt
+++ b/platform/script-debugger/protocol/protocol-reader-runtime/src/org/jetbrains/jsonProtocol/OutMessage.kt
@@ -153,7 +153,8 @@ open class OutMessage() {
     writer.endArray()
   }
 
-  fun writeStringList(name: String, value: Collection<String>) {
+  fun writeStringList(name: String, value: Collection<String>?) {
+    if (value == null) return
     beginArguments()
     JsonWriters.writeStringList(writer, name, value)
   }