The problem, in most cases, is due to incompatible Cydia tweaks or packages. Or may be due to an impending upgrade that you failed to do on Cydia.
Anyway, here are some ways to fix “Exit Safe Mode” the error and troubleshoot the safe mode problem on your iPhone.
Usually, a respring should fix the problem but in some cases, it doesn’t. For me, respring did fix the issue a little earlier. However, if you can’t respring, you’ll need to reboot. When you tap on ‘Exit Safe Mode’ on the statusbar, you’ll get an option to reboot. If things work fine after a reboot, you’re safe.
Update Cydia Packages
If there are some packages waiting to be updated in Cydia, it is better to update them (but check out with the developer/package if the update doesn’t cause any issues. It happens a lot of times). Once you’ve updated, reboot your device. If things work fine, the iPhone should reboot normally.
Remove Erratic/Incompatible Packages
If it still doesn’t work and you are forced to log into safe mode automatically, it’s time to do some spring cleaning in Cydia. Open Cydia and remove packages that you recently installed (mostly the ones after which the auto-safe-mode problem started). Queue them up if there are a lot of packages to be removed. And then remove them. Reboot the iPhone to see if it boots up correctly.
Reset all setting your iPhone, iPad, iPod touch
To erase your iPhone, iPad, or iPod touch, tap Settings > General > Reset > Erase All Content and Settings.
You can use the steps below to restore your device to factory settings and remove all settings and information. Depending on your device, it can take a few minutes to completely erase your data.
If things still don’t work normally, you might have to bite the bullet and rejailbreak your iOS device. It’s usually not recommended but I’d rather vote for it if things are really that bad.
But if things really don’t work at all, you might have to restore your iOS device. But be sure that the problem you’re trying to nail down persists even after you’ve tried all the previous methods. If, even after removing all Cydia packages that you installed (not the ones that Cydia comes bundled with), your iPhone goes berserk and reboots to safe mode, you should try to restore it.
Resource: Sovann Pecheth