ESP32 upload fails with COM port in use
Uploads fail with a COM port in use error on Windows because another program or a monitor still holds the ESP32 serial port.
Tier II · Emerging Problems that are still building up.
3 public reports · first reported 24 August 2026 · last reported 25 August 2026
What's going wrong
Windows users uploading firmware to ESP32 boards in PlatformIO get a COM port in use error.
AI-assisted: written with the help of AI from the reports. The idea report has the full summary.
In the idea report
- The full summary.
- The products the 3 reports are about, and how many came each month.
- Related problems.
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