diff --git a/data/inno.iss b/data/inno.iss
index d3263ab6d9..e19c203b3b 100644
--- a/data/inno.iss
+++ b/data/inno.iss
@@ -12,7 +12,7 @@ AppPublisher=Johannes Pohl
 AppPublisherURL=https://github.com/jopohl/urh
 AppSupportURL=https://github.com/jopohl/urh
 AppUpdatesURL=https://github.com/jopohl/urh
-DefaultDirName={pf}\Universal Radio Hacker
+DefaultDirName={commonpf}\Universal Radio Hacker
 DisableProgramGroupPage=yes
 LicenseFile=..\LICENSE
 OutputDir=..\dist
diff --git a/src/urh/dev/native/ExtensionHelper.py b/src/urh/dev/native/ExtensionHelper.py
index 0cd59b6c0e..d82248dd7c 100644
--- a/src/urh/dev/native/ExtensionHelper.py
+++ b/src/urh/dev/native/ExtensionHelper.py
@@ -57,11 +57,13 @@ def compiler_has_function(compiler, function_name, libraries, library_dirs, incl
     try:
         try:
             file_name = os.path.join(tmp_dir, '{}.c'.format(function_name))
-            f = open(file_name, 'w')
-            f.write('int main(void) {\n')
-            f.write('    %s();\n' % function_name)
-            f.write('}\n')
-            f.close()
+            with open(file_name, 'w') as f:
+                # declare function in order to prevent Clang 12 error (https://github.com/jopohl/urh/issues/811)
+                f.write('void %s();\n' % function_name)
+                f.write('int main(void) {\n')
+                f.write('    %s();\n' % function_name)
+                f.write('}\n')
+
             # Redirect stderr to /dev/null to hide any error messages from the compiler.
             devnull = open(os.devnull, 'w')
             old_stderr = os.dup(sys.stderr.fileno())
diff --git a/src/urh/signalprocessing/ContinuousModulator.py b/src/urh/signalprocessing/ContinuousModulator.py
index 339949f2ea..e9947f8e31 100644
--- a/src/urh/signalprocessing/ContinuousModulator.py
+++ b/src/urh/signalprocessing/ContinuousModulator.py
@@ -25,13 +25,12 @@ def __init__(self, messages, modulators, num_repeats=-1):
         self.modulators = modulators
         self.num_repeats = num_repeats  # -1 or 0 = infinite
 
-        self.ring_buffer = RingBuffer(int(settings.CONTINUOUS_BUFFER_SIZE_MB * 10 ** 6) // 8, dtype=Modulator.get_dtype())
+        self.ring_buffer = RingBuffer(int(settings.CONTINUOUS_BUFFER_SIZE_MB * 1e6) // 8, dtype=Modulator.get_dtype())
 
         self.current_message_index = Value("L", 0)
 
         self.abort = Value("i", 0)
-        self.process = Process(target=self.modulate_continuously, args=(self.num_repeats, ))
-        self.process.daemon = True
+        self.process = Process(target=self.modulate_continuously, args=(self.num_repeats, ), daemon=True)
 
     @property
     def is_running(self):
@@ -40,34 +39,34 @@ def is_running(self):
     def start(self):
         self.abort.value = 0
         try:
-            self.process = Process(target=self.modulate_continuously, args=(self.num_repeats, ))
-            self.process.daemon = True
+            self.process = Process(target=self.modulate_continuously, args=(self.num_repeats, ), daemon=True)
             self.process.start()
         except RuntimeError as e:
-            logger.debug(str(e))
+            logger.exception(e)
 
     def stop(self, clear_buffer=True):
         self.abort.value = 1
-        if clear_buffer:
-            self.ring_buffer.clear()
-        if not self.process.is_alive():
-            return
-
-        try:
-            self.process.join(0.1)
-        except RuntimeError as e:
-            logger.debug(str(e))
 
         if self.process.is_alive():
-            self.process.terminate()
-            self.process.join()
+            try:
+                self.process.join(1.5)
+            except RuntimeError as e:
+                logger.exception(e)
+                self.process.terminate()
+
+        if clear_buffer:
+            self.ring_buffer.clear()
 
         logger.debug("Stopped continuous modulation")
 
     def modulate_continuously(self, num_repeats):
         rng = iter(int, 1) if num_repeats <= 0 else range(0, num_repeats)  # <= 0 = forever
         for _ in rng:
+            if self.abort.value:
+                return
+
             start = self.current_message_index.value
+
             for i in range(start, len(self.messages)):
                 if self.abort.value:
                     return
@@ -82,5 +81,7 @@ def modulate_continuously(self, num_repeats):
 
                     # Wait till there is space in buffer
                     time.sleep(self.WAIT_TIMEOUT)
+
                 self.ring_buffer.push(modulated)
+
             self.current_message_index.value = 0
diff --git a/src/urh/simulator/Simulator.py b/src/urh/simulator/Simulator.py
index 75638cb4fe..d9467a75a6 100644
--- a/src/urh/simulator/Simulator.py
+++ b/src/urh/simulator/Simulator.py
@@ -353,6 +353,7 @@ def process_message(self):
                 received_msg.decoder = new_message.decoder
                 received_msg.message_type = new_message.message_type
 
+                self.log_message("Message {}: Check whether received data matches".format(msg.index()))
                 check_result, error_msg = self.check_message(received_msg, new_message, retry=retry,
                                                              msg_index=msg.index())
 
diff --git a/tests/test_continuous_modulator.py b/tests/test_continuous_modulator.py
index 5b7eb86de3..053c4f2928 100644
--- a/tests/test_continuous_modulator.py
+++ b/tests/test_continuous_modulator.py
@@ -20,7 +20,7 @@ def test_modulate_continuously(self):
         self.assertTrue(continuous_modulator.ring_buffer.is_empty)
         continuous_modulator.start()
         self.assertTrue(continuous_modulator.process.is_alive())
-        time.sleep(1.5)
+        time.sleep(2)
         self.assertFalse(continuous_modulator.ring_buffer.is_empty)
         continuous_modulator.stop()
         self.assertFalse(continuous_modulator.process.is_alive())