Cant update openelec box from libreelec 7.0.2

Hello,
I have an OPENELEC box running libreelec 7.0.2.
when i tried to do a manual update from the program nothing happened.
when i downloaded the update file (LibreELEC-WeTek_Play.arm-7.0.3.img) and put it in the update folder after a reboot the device hanged on a screen saying decompressing file for a while and then started the program without preforming the update.
any ideas??
i also have a RPi 3 which i updated with no problems...
Thank you!

Quote from bromerzz

To update an existing installation you need to use the .tar file not the .img file.

Thank you for your reply are you sure about what you are saying?
I used the img file to update my RPi, i thing that Libreelec Unlike Openelec uses img files to update.
also, if you are sure can you point me to the correct file the only reference i found (in the picture) is a img file (the tar file is for updates from openelec and the zip file for a fresh install)