Ok, so I tried it again. I'm still getting the same error. At "Verifying current system" when I'm applying the 206 (208) update, it says:
assert failed: apply_patch_check("MTD:boot8388608:fe086e1f547082 blah blah blah)
E: Error in /tmp/sideload/package.zip
(Status 7)
Installation aborted.
assert failed: apply_patch_check("MTD:boot8388608:fe086e1f547082 blah blah blah)
E: Error in /tmp/sideload/package.zip
(Status 7)
Installation aborted.