Hi, Just upgraded the Keil 5.10 to 5.11 to have STM32L0 support.
When trying to debug my application I get: "st-link usb communication error" and debug fails.
I have no problem connecting to my board using ST-Link Utility.
The 5.10 works fine - no issues with connecting to the ST-link.
I use the latest ST-link drivers and firmware (STLinkUSBDriver.dll v4.3.3.0, ST-LINK Firmware version : V2J21M5)
Bogdan