Hello,
I have try to downgrade from v6.42.1 to 6.36
and this is waht I get :
RouterBOOT booter 6.42.1
RouterBoard 411U
CPU frequency: 300 MHz
Memory size: 32 MiB
NAND size: 128 MiB
Press any key within 2 seconds to enter setup..
loading kernel... OK
setting up elf image... OK
jumping to kernel code
Starting...
Generating SSH 1024bit DSA host key...
Too many levels of symbolic links
same
downgrade from 6.42.3 to 6.40.8 (bugfix) (because has error with backup: “backup,critical error creating backup file: could not read all configuration files”)
RouterBOOT booter 6.42.3
RouterBoard 1000
CPU frequency: 1333 MHz
Memory size: 512 MiB
NAND size: 64 MiB
Press any key within 2 seconds to enter setup..
loading kernel... OK
setting up elf image... OK
jumping to kernel code
Starting...
Generating SSH 1024bit DSA host key...
Too many levels of symbolic links
recently I downgraded RB433AH from 6.42.1 to 6.40.8 and I had to bring it back to live using Netinstall. Since I had no access via serial line I have no additional information. What happened to you could explain the problem too IMHO.