Hello,

1. Installing BB-rc3 over Attitude Adjustment on TL-WR1043ND-v1 using sysupgrade from GUI while keeping configuration results in web access being cut off after upgrade (both HTTP and HTTPS). The problem seems to be related to missing ubus and mod-tls packages for uhttpd as well as new config being considerably different.

2. Installing BB-rc3 over Attitude Adjustment on Ubiquiti RouterStation Pro using sysupgrade from GUI while keeping configuration files disables all access to the unit (HTTP and HTTPS same issue as in TL-WR1043ND), and failsafe mode followed by TFTP flash is required to regain access. I had sshd installed instead of dropbear which was set to allow root login using authorized_keys only. After sysupgrade, PuTTY reported that dropbear is running on the unit instead of sshd. Furthermore, at the end of flashing an error about being unable to append configuration to partition and bad TRX checksum was reported so due to borked configuration files login was of course impossible via ssh.

In my opinion, sysupgrade should check if dropbear is disabled in startup and if it is, it should look for replacement ssh server and make sure it will be operational after flash and reboot. Same goes for HTTPS, if uhttpd is configured for HTTPS and luci-ssl is installed it should continue working after upgrade. Also, it would be about time to switch to OpenSSH with SFTP support as default, at least for devices with more memory or at least also include /etc/ssh/* in default config backup.

Fix for TP-Link was trivial -- cp /rom/etc/config/uhttpd.conf /etc/config and edit to match previous listening address/port settings. Fix for RouterStation Pro took me a whole day because I had to reconfigure from scratch. It seems that VLAN settings for RS Pro do not get set correctly through GUI -- I cut myself off the device and had to reflash 4 times until I gave up on GUI and set the config by copying preconfigured network file directly from PC. Network config was not overly complicated -- two unmanaged interfaces (VLAN 20, 30) and one admin interface (VLAN 10) but it refused to apply correctly from GUI. I can attach config if needed.

Finally, config backup for some reason contains uhttpd.crt and uhttpd.key twice.