So, I have unlocked my Samsung Nexus S that runs on Android 2.3.1 and i have rooted it. The problem now is that I cant open wifi anymore, it keeps telling me "error" whenever I click on wifi ..
Why is this happening? How to fix it?
I fixed this by restoring only the android "boot" module from the original rom backup:
I used the clockworkmod recovery which can also be installed from the rooted phone using the "rom manager" app. But instead of making a whole recovery, i simply went into advanced recovery options, selected the above mentioned backup folder, and selected to restore only the "boot" module:
This post describes how to restore your nexus s to original stock android and provides a backup of the original rom: http://forum.xda-developers.com/showthread.php?t=884093
The same happens for me. When I use the 'fastboot boot *.img' command from my pc, the Nexus S boots into some (e.g. Netarchy) kernel, and everything except WiFi works.
I assume the problems lies with some kernel-modules (which can actually be on the device memory, outside of the kernel) which do not match the new kernel. Since some of the modules (e.g. for the gsm/gprs radio) are closed source, they are not updated to match newer kernels.
So you could try older kernel versions, or wait for updates from Samsung