Mikrotik rb750gr3 can't sysupgrade

i installed openwrt to mikrotik rb750gr3 but i used the snapshot that is linked on the wiki:

i tried to sysupgrade both via web gui and via ssh, to a 18.06.01 and 18.06.04 version, but each time i get an error saying "image not compatible" and then "requirement rb750g3 , available rb750gr3" or similar. so both the required and available version are the same, but it won't let me upgrade.

can someone help me how to install the latest possible version?

anyone? rb750 is a nice cheap gigabit router, weird nobody is using it...

Just try to use the command prompt. Some devices have downgrade issues due to a change in the firmware between versions.