How do I repair my Motorola Defy rebooting instantly after start-up? I installed a few different operating systems (“ROMs”) on my Motorola Defy and I decided to (temporarily) go back to the original one, also known as “stock”, by using an SBF file. But now, whenever I try to start up my phone, it reboots almost instantly. I cannot do anything.

I tried booting in “Safe mode” as explained here (Power button + both volume keys). But that did not change anything. I also tried reflashing my SBF files multiple times, to no success.
Boot into recovery with Power button + lower volume key. Then, in the recovery mode menu, select “Factory reset”. This should delete all previous configurations from your previous ROMs that may interfere with your current installation.