# Fatal esptool.py error occurred: Write timeout

**URL:** <https://forum.arduino.cc/t/fatal-esptool-py-error-occurred-write-timeout/1225320>\
**Category:** Uploading\
**Created:** [February 18, 2024, 7:32am UTC](https://forum.arduino.cc/t/fatal-esptool-py-error-occurred-write-timeout/1225320 "2024-02-18T07:32:23Z")\
**Posts on this page:** 1\
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**Author:** ![paulpaulson](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paulpaulson/32/363643_2.png) [@paulpaulson](https://forum.arduino.cc/u/paulpaulson)\
**Post date:** [February 18, 2024, 7:34am UTC](https://forum.arduino.cc/t/fatal-esptool-py-error-occurred-write-timeout/1225320/2 "2024-02-18T07:34:47Z")

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> [@A fatal esptool.py error occurred: Cannot configure port, something went wrong](https://forum.arduino.cc/t/a-fatal-esptool-py-error-occurred-cannot-configure-port-something-went-wrong/1225308/4):
>
> OK, great. This "PermissionError(13, 'A device attached to the system is not functioning.', None, 31)" error can occur when uploading to the boards that use specific batches of the [WCH CH340 USB chip](http://www.wch-ic.com/products/CH340.html). We have noticed a characteristic of those sketchy CH340 chips is the lack of labeling (normally "WCH CH340G" is written on them), as is the case with your chip. The problem only occurs when using the latest version of the CH340 driver. The affected users have reported that doing a "roll back" to a…

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