I am trying to upgrade Openwrt from 18.07.6 to 19.07.1, using the firmware upgrade option in Luci, but it fails. I have previously successfully upgraded from version 15 to 18.07.6.
Anyone has an idea why? or any experience or solution?
Thank you for the tip. It helped.
Using your method, I discovered that the router probably had not enough memory.
After deleting files and make space, I was able to upgrade.