Issue With Trying To Verify/Compile Software For D1 Mini


I have done a fair amount of searching through various forums to find instances of a similar issue with little success. I did find one thread in the Arduino forum, but I did not see a clear resolution to the problem. I am hoping I can provide more detail and hopefully someone will have an idea why I am experiencing this issue.

I have a lot of experience with the Arduino IDE along with Arduino Uno & Mega HW platforms. I have not experienced any significant issues in the past. I am now trying to use an ESP-8266 Wifi module platform called the Wemos D1 Mini. There are many tutorials/examples online showing how to program the Wemos D1 Mini using the Arduino IDE. I have followed those instructions to the best of my ability, but I keep receiving the same error when trying to Verify/Compile some example code:

“open sketch\Blink.ino.cpp: The process cannot access the file because it is being used by another process.
Error compiling for board WeMos D1 R2 & mini.”

I will do my best to describe all of the steps I took up until this point:

PC Operating System : Windows 10
Arduino IDE Version : 1.8.5
Hardware Module : Wemos D1 Mini V3.0.0 (

  1. Installed Driver For CH430G With Wemos D1 Mini Plugged In (CH340G Driver Installation.PNG)
  2. Added “” To Additional Boards Manager in Arduino IDE Preferences. (Additional Boards Manager.PNG)
  3. Installed “ESP8266 Community” From Boards Manager in Arduino IDE (ESP8266 Community Board Manager.PNG)
  4. Selected Port COM4
  5. Selected Board Wemos D1 R2 & mini (Board Selection.PNG)
  6. Selected “Blink” Example from ESP8266 Examples (Blink Example.PNG)
  7. Clicked Verify/Compile (Blink SW And Failed Compile.PNG)

Hopefully someone has encountered a similar problem and can help me out. Any sort of input/response would be greatly appreciated. Thank you.


CH340G Driver Installation.PNG

Board Selection.PNG

This sort of error could be caused by your antivirus software. Try TEMPORARILY disabling your antivirus for a single compilation to see if the problem goes away, then turn the antivirus back on. If the problem doesn't occur with the antivirus off you will need to adjust the settings of your antivirus to whitelist the appropriate file, folder, or process so it doesn't interfere with compilation.

Thank you Pert,

You nailed it. I temporarily disabled my antivirus program, and sure enough it compiled. This was a red flag to me that the anitvirus SW and this new arduino library were not playing well together.

From memory, I originally was trying to install the drivers with a faulty cable. In a desperate act to get it to work, I installed a driver from a different site. This may have corrupted my computer and my antivirus software was latching onto it.

I just reset my entire OS and re-installed everything from scratch. Everything is working like a charm.

Thank you for the help. Much appreciated.

Glad to hear it's working now. Enjoy!