Can no longer flash new code after Error Message: Mutex lock failed

I received the error below on my device that uses the STML476 MCU. The device uses an LPC11U35 for drag and drop flash programing. The drag and drop update no longer works since this error is occurring. Is there a way to reset/clear this error to allow reprograming?

++ MbedOS Error Info ++
Error Status: 0x80020115 Code: 277 Module: 2
Error Message: Mutex lock failed
Location: 0x8016525
Error Value: 0xFFFFFFFA
Current Thread: Id: 0x20003938 Entry: 0x801DEA9 StackSize: 0x1000 StackMem: 0x20002938 SP: 0x20017F40
For more info, visit: https://armmbed.github.io/mbedos-error/?error=0x80020115
-- MbedOS Error Info --

Start with the reported Mbed OS error 0x80020115 and the STM32L476/LPC11U35 device combination, then read the existing 41-comment discussion for reproduction details and proposed causes. Done means identifying a supported way to clear or recover from the mutex-lock failure so drag-and-drop flashing works again.

Written by the indexing model from the issue text.