I was refering to extracting to same place, e.g. Desktop, and manually adding lib files to project, without creator.
Extracting to the same directory as downloaded ZIP file, so Workbench can notice it fails, because of “Path too long” error. The ZIP path itself (C:\Users\User\AppData\Roaming\Ac6\SW4STM32\firmwares.tmp_STM32FirmwareInstall_2364644042357059320.zip) is 103 characters. ZIP also contains long paths which adds to a number grater than 260 characters limit. An example:
This is 245 characters, near the limit. And in the ZIP there are file with even longer names. So I suspect it can be the cause of creator failing to extract the firmware.
Related article: http://news.softpedia.com/news/microsoft-removes-260-characters-path-length-limit-in-windows-10-redstone-504596.shtml