Is this any wifi, or just one particular wifi spot? Did you fully reboot the phone?
Things to try:
forget wifi connection and then reconnect
reboot wifi router
reset network settings and then reconnect with wifi.
We have to make sure your phone can connect to WIFI. We are here to help. Without speaking with you, the first two things I would have you do is the check for new software updates. I would also have you reset your network settings. I have provided links below that will give you the instructions?
Software update: http://vz.to/2b9n5wb
Reset network settings: http://vz.to/2bfgteW
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