diff --git a/apps/file_manager/ui.cpp b/apps/file_manager/ui.cpp
index 6b238c4..435af3c 100644
--- a/apps/file_manager/ui.cpp
+++ b/apps/file_manager/ui.cpp
@@ -548,7 +548,7 @@ void ThumbnailResize(uint32_t *bits, uint32_t originalWidth, uint32_t originalHe
 void ThumbnailGenerateTask(Instance *, Task *task) {
 	EsMessageMutexAcquire();
 	Thumbnail *thumbnail = thumbnailCache.Get(&task->id);
-	bool cancelTask = !thumbnail || thumbnail->referenceCount == 0;
+	bool cancelTask = !thumbnail || thumbnail->referenceCount == 0 || EsWorkIsExiting();
 	EsMessageMutexRelease();
 
 	if (cancelTask) {
@@ -593,13 +593,6 @@ void ThumbnailGenerateTask(Instance *, Task *task) {
 	if (targetWidth == originalWidth && targetHeight == originalHeight) {
 		targetBits = originalBits;
 	} else {
-		targetBits = (uint32_t *) EsHeapAllocate(targetWidth * targetHeight * 4, false);
-
-		if (!targetBits) {
-			EsHeapFree(originalBits);
-			return; // Allocation failure; could not resize the image.
-		}
-
 		ThumbnailResize(originalBits, originalWidth, originalHeight, targetWidth, targetHeight);
 		targetBits = (uint32_t *) EsHeapReallocate(originalBits, targetWidth * targetHeight * 4, false);
 	}
diff --git a/desktop/api.cpp b/desktop/api.cpp
index c7adfb3..2942e62 100644
--- a/desktop/api.cpp
+++ b/desktop/api.cpp
@@ -145,6 +145,8 @@ struct {
 	EsHandle workAvailable;
 	EsMutex workMutex;
 	Array<Work> workQueue;
+	Array<EsHandle> workThreads;
+	volatile bool workFinish;
 } api;
 
 ptrdiff_t tlsStorageOffset;
@@ -862,7 +864,17 @@ EsMessage *EsMessageReceive() {
 				// Desktop tracks the number of instances it owns, so it needs to know when it exits.
 				ApplicationProcessTerminated(EsProcessGetID(ES_CURRENT_PROCESS));
 			} else {
+				api.workFinish = true;
+				if (api.workAvailable) EsEventSet(api.workAvailable);
+				EsMessageMutexRelease();
+
+				for (uintptr_t i = 0; i < api.workThreads.Length(); i++) {
+					EsWaitSingle(api.workThreads[i]);
+					EsHandleClose(api.workThreads[i]);
+				}
+
 #ifdef DEBUG_BUILD
+				EsMessageMutexAcquire();
 				FontDatabaseFree();
 				FreeUnusedStyles(true /* include permanent styles */);
 				theming.loadedStyles.Free();
@@ -875,8 +887,9 @@ EsMessage *EsMessageReceive() {
 				gui.allWindows.Free();
 				calculator.Free();
 				HashTableFree(&gui.keyboardShortcutNames, false);
-				EsHandleClose(api.workAvailable); // TODO Waiting for all work to finish.
+				if (api.workAvailable) EsHandleClose(api.workAvailable);
 				EsAssert(!api.workQueue.Length());
+				api.workThreads.Free();
 				api.workQueue.Free();
 				MemoryLeakDetectorCheckpoint(&heap);
 				EsPrint("ES_MSG_APPLICATION_EXIT - Heap allocation count: %d (%d from malloc).\n", heap.allocationsCount, mallocCount);
@@ -1893,6 +1906,10 @@ void EsTimerCancel(EsTimer id) {
 	EsMutexRelease(&api.timersMutex);
 }
 
+bool EsWorkIsExiting() {
+	return api.workFinish;
+}
+
 void WorkThread(EsGeneric) {
 	while (true) {
 		EsWait(&api.workAvailable, 1, ES_WAIT_NO_TIMEOUT);
@@ -1907,28 +1924,38 @@ void WorkThread(EsGeneric) {
 				work.callback(work.context);
 			} else {
 				EsMutexRelease(&api.workMutex);
+
+				if (api.workFinish) {
+					EsEventSet(api.workAvailable); // Wake up another thread.
+					return;
+				} else {
+					break;
+				}
 			}
 		}
 	}
 }
 
-void EsWorkQueue(EsWorkCallback callback, EsGeneric context) {
+EsError EsWorkQueue(EsWorkCallback callback, EsGeneric context) {
 	EsMutexAcquire(&api.workMutex);
 
 	if (!api.workAvailable) {
 		api.workAvailable = EsEventCreate(true /* autoReset */);
-		EsThreadInformation thread = {};
+	}
 
-		for (uintptr_t i = 0; i < EsSystemGetOptimalWorkQueueThreadCount(); i++) {
-			EsThreadCreate(WorkThread, &thread, nullptr);
-			EsHandleClose(thread.handle);
-		}
+	EsThreadInformation thread = {};
+
+	while (api.workThreads.Length() < EsSystemGetOptimalWorkQueueThreadCount()) {
+		EsError error = EsThreadCreate(WorkThread, &thread, nullptr);
+		if (error != ES_SUCCESS) return error;
+		api.workThreads.Add(thread.handle);
 	}
 
 	Work work = { callback, context };
-	api.workQueue.Add(work);
+	bool success = api.workQueue.Add(work);
 	EsMutexRelease(&api.workMutex);
 	EsEventSet(api.workAvailable);
+	return success ? ES_SUCCESS : ES_ERROR_INSUFFICIENT_RESOURCES;
 }
 
 #ifndef ENABLE_POSIX_SUBSYSTEM
diff --git a/desktop/os.header b/desktop/os.header
index 612f719..35c929f 100644
--- a/desktop/os.header
+++ b/desktop/os.header
@@ -1997,7 +1997,8 @@ function EsError EsThreadCreate(EsThreadEntryCallback entryFunction, EsThreadInf
 function EsObjectID EsThreadGetID(EsHandle thread);
 function void EsThreadTerminate(EsHandle thread); 
 
-function void EsWorkQueue(EsWorkCallback callback, EsGeneric context);
+function EsError EsWorkQueue(EsWorkCallback callback, EsGeneric context);
+function bool EsWorkIsExiting();
 
 // Memory.
 
diff --git a/kernel/x86_64.cpp b/kernel/x86_64.cpp
index 8ed8068..2307209 100644
--- a/kernel/x86_64.cpp
+++ b/kernel/x86_64.cpp
@@ -996,6 +996,7 @@ extern "C" void InterruptHandler(InterruptContext *context) {
 
 				while (rbp && traceDepth < 32) {
 					uint64_t value;
+					if (!MMArchIsBufferInUserRange(rbp, 16)) break;
 					if (!MMArchSafeCopy((uintptr_t) &value, rbp + 8, sizeof(uint64_t))) break;
 					EsPrint("\t%d: %x\n", ++traceDepth, value);
 					if (!value) break;
diff --git a/util/api_table.ini b/util/api_table.ini
index 7e9073d..ef6387e 100644
--- a/util/api_table.ini
+++ b/util/api_table.ini
@@ -454,3 +454,4 @@ EsFontDatabaseLookupByName=452
 _EsWindowGetHandle=453
 _EsUISetFont=454
 EsWorkQueue=455
+EsWorkIsExiting=456