Ok Greg....
I just downloaded the version from your link... it's the same as before 9.2.0.110
I'm getting the same errors... the Cisco Wireless LAN Controller says File Transfer Failed! The SolarWinds TFTP server says Interrupted by client, cause: Path cannot be null (some strange ascii character)Parameter name: path..... next line says Transmission failed. Illegal characters in path.
The TFTP server root directory is: C:\TFTP-Root
I have a folder under it C:\TFTP-Root\WLC
I've tried the following:
/TFTP-Root/WLC/
/TFTP-Root/
/
\ (The WLC automatically changed the path to \/ (backslash forwardslash.... not a capital letter V)
Any ideas?