jmomo:

I think I am also seeing this on my own custom device build on an ipq806x.

root@LEDE:/tmp# sysupgrade openwrt-ipq806x-trendnet_tew827dru-squashfs-sysupgrad
e.bin
Image metadata not found
Use sysupgrade -F to override this check when downgrading or flashing to vendor firmware
Image check 'fwtool_check_image' failed.

I think I first started seeing this back on LEDE v17.06.05. Wasn't happening back on 03 or 04. Not positive about that though.

Doing a sysupgrade with -F results in success, including config restore, so this is probably just a problem with whatever this magic metadata check is.

jmomo:

Looks like I fixed my own issue and might help you with yours. Apparently at some point a "append-metadata" Makefile option was added and I didn't notice. I just need to append this to my IMAGE/sysupgrade.tar in the Makefile.

hgl:

I'm also having this issue. Built a x86 image, but sysupgrade complained "Image metadata not found".

@j I failed to find the append-metadata" Makefile option, is it something in menuconfig? This issue is about x86, and there seems to be no such option when you select the x86 architecture.