When using LG UP to flash kdz file to upgrade/unbrick/restore LG devices, You may experience the “Invalid kdz” issue.
“while trying to flash a kdz file to restore my LG H918 ,I was getting an error and wasnt able to flash the file kept saying invalid kdz file.”
To solve the “Invalid KDZ file” issue,
Step 1, please make sure that you download the original firmware from LG Server – Your firmware download urls should looks like “http://csmgdl.lgmobile.com/dn/downloader.dev?fileKey=xxx”.
Step 2, Please uninstall/remove LG bridge or any other LG Software completely from your Computer
Step 3, Please install latest LG USB drivers for your phone.
Step 4, Install Latest LG UP software, LG UP DLL for your phone.
Step 5, Put your phone into download mode first and then run the LG UP. If you did not put your phone to download mode and let LG UP to detect your phone, LG UP may not detect the correct usb port.
Step 6, Please check the ports number showed on LG UP match the usb ports number used by your phone. Go control panel device manager -> LG android device
You can watch below video shared by RisingTech – Learn how to check and change the USB ports numbers.