diff --git a/HISTORY.rst b/HISTORY.rst
index 858f102c..9addc2bf 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -15,6 +15,8 @@ PlatformIO Core 5
 * Improved listing of `multicast DNS services <https://docs.platformio.org/page/core/userguide/device/cmd_list.html>`_
 * Check for debug server's "ready_pattern" in "stderr"
 * Upgraded build engine to the SCons 4.1 (`release notes <https://scons.org/scons-410-is-available.html>`_)
+* Fixed a "UnicodeDecodeError: 'utf-8' codec can't decode byte" when using J-Link for a firmware uploading on Linux (`issue #3804 <https://github.com/platformio/platformio-core/issues/3804>`_)
+* Fixed an issue with Python 3.8+ on Windows when network drive is used (`issue #3417 <https://github.com/platformio/platformio-core/issues/3417>`_)
 
 5.0.4 (2020-12-30)
 ~~~~~~~~~~~~~~~~~~
diff --git a/platformio/proc.py b/platformio/proc.py
index d9df0a3b..24640c38 100644
--- a/platformio/proc.py
+++ b/platformio/proc.py
@@ -32,7 +32,10 @@ from platformio.compat import (
 class AsyncPipeBase(object):
     def __init__(self):
         self._fd_read, self._fd_write = os.pipe()
-        self._pipe_reader = os.fdopen(self._fd_read)
+        if PY2:
+            self._pipe_reader = os.fdopen(self._fd_read)
+        else:
+            self._pipe_reader = os.fdopen(self._fd_read, errors="backslashreplace")
         self._buffer = ""
         self._thread = Thread(target=self.run)
         self._thread.start()
@@ -68,10 +71,10 @@ class BuildAsyncPipe(AsyncPipeBase):
         line = ""
         print_immediately = False
 
-        for byte in iter(lambda: self._pipe_reader.read(1), ""):
-            self._buffer += byte
+        for char in iter(lambda: self._pipe_reader.read(1), ""):
+            self._buffer += char
 
-            if line and byte.strip() and line[-3:] == (byte * 3):
+            if line and char.strip() and line[-3:] == (char * 3):
                 print_immediately = True
 
             if print_immediately:
@@ -79,12 +82,12 @@ class BuildAsyncPipe(AsyncPipeBase):
                 if line:
                     self.data_callback(line)
                     line = ""
-                self.data_callback(byte)
-                if byte == "\n":
+                self.data_callback(char)
+                if char == "\n":
                     print_immediately = False
             else:
-                line += byte
-                if byte != "\n":
+                line += char
+                if char != "\n":
                     continue
                 self.line_callback(line)
                 line = ""