Legacy drivers often caused the dongle to "disappear" after the computer went to sleep. The new driver implements proper USB selective suspend handling.
Only get the driver from the official source: uda v5 dongle driver new
Old drivers locked the COM port to a single application. The new driver allows two different programs (e.g., a logger and a flasher) to access the same dongle simultaneously, provided they use read-only sharing. Legacy drivers often caused the dongle to "disappear"
Even with the new driver, problems can arise. Here are the top five issues and solutions. uda v5 dongle driver new