I have the same issue (I'm under 10.11.2 safari 9.0.2). My friend under 10.10.5 and safari upgraded on 9.0.2 has the same issue. We could not type anything on the address bar...
Seems that is an issue on safari?
On the logs:
I can see a spam of the following safari message:
1/27/16 10:08:47.094 AM Safari[22938]: *** +[NSURLComponents initWithURL:resolvingAgainstBaseURL:]: nil URLString parameter
1/27/16 10:08:47.095 AM Safari[22938]: (
0 CoreFoundation 0x00007fff87432ae2 __exceptionPreprocess + 178
1 libobjc.A.dylib 0x00007fff85534f7e objc_exception_throw + 48
2 CoreFoundation 0x00007fff8743298d +[NSException raise:format:] + 205
3 Foundation 0x00007fff8ffe1e20 -[__NSConcreteURLComponents initWithURL:resolvingAgainstBaseURL:] + 120
4 Foundation 0x00007fff8ffe1d8e +[NSURLComponents componentsWithURL:resolvingAgainstBaseURL:] + 54
5 SafariShared 0x00007fff94de73db -[WBSParsecSearchSession _searchURLForQuery:baseURL:] + 58
6 SafariShared 0x00007fff94de733f -[WBSParsecSearchSession _searchURLForQuery:] + 83
7 SafariShared 0x00007fff94de6f2a -[WBSParsecSearchSession _sendWarmupRequest] + 187
8 SafariShared 0x00007fff94de6bfe -[WBSParsecSearchSession initWithClient:] + 335
9 Safari 0x00007fff813b5683 _ZN6Safari35UnifiedFieldCompletionListGenerator35startParsecSearchSessionIfNece ssaryEv + 143
10 Safari 0x00007fff813b539e _ZN6Safari35UnifiedFieldCompletionListGenerator19setStringToCompleteEP8NSString NS0_17AllowParsecSearchE + 908
11 Safari 0x00007fff813b5010 _ZN6Safari35UnifiedFieldCompletionListGenerator19setStringToCompleteEP8NSString + 14
12 Safari 0x00007fff813a6f10 ___ZN6Safari32UnifiedFieldCompletionController24userTypedStringDidChangeEv_bloc k_invoke + 29
13 SafariShared 0x00007fff94dc438f +[NSTimer(WBSNSTimerExtras) _safari_blockTimerDidFire:] + 64
14 Foundation 0x00007fff8ff9a85b __NSFireTimer + 95
15 CoreFoundation 0x00007fff87378bc4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
16 CoreFoundation 0x00007fff87378853 __CFRunLoopDoTimer + 1075
17 CoreFoundation 0x00007fff873f6e6a __CFRunLoopDoTimers + 298
18 CoreFoundation 0x00007fff87333cd1 __CFRunLoopRun + 1841
19 CoreFoundation 0x00007fff87333338 CFRunLoopRunSpecific + 296
20 HIToolbox 0x00007fff878af935 RunCurrentEventLoopInMode + 235
21 HIToolbox 0x00007fff878af76f ReceiveNextEventCommon + 432
22 HIToolbox 0x00007fff878af5af _BlockUntilNextEventMatchingListInModeWithFilter + 71
23 AppKit 0x00007fff895db0ee _DPSNextEvent + 1067
24 AppKit 0x00007fff899a7943 -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 454
25 Safari 0x00007fff8101637f -[BrowserApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 252
26 AppKit 0x00007fff895d0fc8 -[NSApplication run] + 682
27 AppKit 0x00007fff89553520 NSApplicationMain + 1176
28 libdyld.dylib 0x00007fff921385ad start + 1
29 ??? 0x0000000000000001 0x0 + 1
)
And below a screenshot of my address bar.