I was using uV4.2.1 for the STM32L-Discovery. After I changed the MSI frequency to range 0 (65,536 kHz) and debugged, the program ran slowly as expected on the board. However, whenever I clicked debug again for another program, the "internal command error" appeared and I could not proceed. Rebooting and reloading the uV4 did not help. What was the error I made ? How can I recover the board ?
I received the same error. I had originally loaded one of the demo programs on the STM32L-Discovery board and then tried to load a different demo a few minutes later. I removed the two jumpers that link the debugged to the target device on the demo board, and told MDK to reflash the device. Of course the flash procedure failed with some error similar to "No Target Found". I then reconnected the jumpers and tried again. Everything worked as it should.