Just for real life reference, here is the kind of thing AJ is meaning…
Late last year there were a few people who had iOS 8 jailbreaks. These people simply updated to iOS 9 when it was released and did not restore to it.
When the first iOS 9 jailbreak dropped they jailbroke and then tried to install tweaks. THAT is when this caught up with them. They still had the remains of the previous iOS 8 jailbreak hanging around and Cydia would not allow any tweak installs without removal of the parts of the previous jailbreak that were still present.
But Cydia also would not allow the removal of the pieces of the past jailbreak. So, these people were stuck.
It meant that they had to restore. For some of them who had bad timing on this the restore they had to do was to a version of iOS that was not jailbreakable (at the time). Hence they lost their jailbreak.
All because they chose to update instead of restoring way back when iOS 9 was released.
ALWAYS restore to the latest version when you are jailbroken. NEVER just update to it.
