Spotlight Repeatedly Silently Crashing

I have two Macs (10.12.6) on which spotlight is repeatedly silently crashing. What I mean by this is as I'm typing into spotlight, the search bar goes away, the search icon disappears from the menu bar, and then reappears a split second later. There is no specific phrase I'm entering that causes this, and it occurs almost every time I use spotlight for these computers. Restarts did not solve the issue. The second computer started exhibiting this behavior after a software update last night (security update beta), but the primary computer has been doing this for a while (I'm not sure when it started). EDIT: Spotlight works in Safe Mode, but after shutting down Safe Mode and booting regularly, Spotlight fails again.

First computer noticed on: Mac Pro 2009 (5,1) macOS 10.12.6 build 16G1510.
Second computer noticed on: MacBook Pro 15" Late 2013 macOS 10.12.6 build 16G1614.

Although the crash doesn't seem to generate a crash report, here is what I pulled from the System.log. EDIT: I have added an uninterrupted section of the System.log in which two crashes are present. Note that the two breaks are just where I'm noting the crashes, but these lines are all sequential in the System.log:

Oct 16 16:13:30 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.imfoundation.IMRemoteURLConnectionAgent): Unknown key for integer: _DirtyJetsamMemoryLimit
Oct 16 16:13:30 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.pid.IDECacheDeleteAppExtension.3356): Path not allowed in target domain: type = pid, path = /Applications/Xcode.app/Contents/Frameworks/IDEKit.framework/Versions/A/XPCServices/IDETouchBarSimulatorService.xpc error = 147: The specified service did not ship in the requestor's bundle, origin = /Applications/Xcode.app/Contents/PlugIns/IDECacheDeleteAppExtension.appex
Oct 16 16:13:30 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.pid.IDECacheDeleteAppExtension.3356): Path not allowed in target domain: type = pid, path = /Applications/Xcode.app/Contents/SharedFrameworks/LLDB.framework/Versions/A/XPCServices/RootDebuggingXPCService.xpc error = 147: The specified service did not ship in the requestor's bundle, origin = /Applications/Xcode.app/Contents/PlugIns/IDECacheDeleteAppExtension.appex

FIRST CRASH:

Oct 16 16:14:15 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.Spotlight[962]): Service exited due to signal: Illegal instruction: 4 sent by exc handler[0]
Oct 16 16:14:15 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.ReportCrash[3368]): Endpoint has been activated through legacy launch(3) APIs. Please switch to XPC or bootstrap_check_in(): com.apple.ReportCrash
Oct 16 16:14:23 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.imfoundation.IMRemoteURLConnectionAgent): Unknown key for integer: _DirtyJetsamMemoryLimit
Oct 16 16:14:24 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.Spotlight[3367]): Service exited due to signal: Illegal instruction: 4 sent by exc handler[0]
Oct 16 16:14:24 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent.Development): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:24 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.Plugin.32): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:24 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:24 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.Plugin.64): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:29 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.Safari.History[3373]): Service did not exit 5 seconds after SIGTERM. Sending SIGKILL.
Oct 16 16:14:30 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.imfoundation.IMRemoteURLConnectionAgent): Unknown key for integer: _DirtyJetsamMemoryLimit
Oct 16 16:14:31 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent.Development): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:31 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.Plugin.32): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:31 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:31 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.Plugin.64): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:14:32 Noahs-Macbook-Pro diagnosticd[3381]: System mode client started - Console (3377) - mode: 0x8
Oct 16 16:14:36 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.imfoundation.IMRemoteURLConnectionAgent): Unknown key for integer: _DirtyJetsamMemoryLimit
Oct 16 16:14:43 Noahs-Macbook-Pro Console[3377]: BUG in libdispatch client: kevent[EVFILT_MACHPORT] monitored resource vanished before the source cancel handler was invoked
Oct 16 16:14:50 Noahs-Macbook-Pro cloudd[867]: notify name "com.apple.cloudkit.pcs.flushCaches" has been registered 20 times - this may be a leak
Oct 16 16:15:13 --- last message repeated 2 times ---
Oct 16 16:15:13 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.imfoundation.IMRemoteURLConnectionAgent): Unknown key for integer: _DirtyJetsamMemoryLimit
Oct 16 16:15:13 --- last message repeated 1 time ---
Oct 16 16:15:13 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent.768E1C08-18AC-4242-A7C4-AC9D1290B18F[3391]): Service exited due to signal: Killed: 9 sent by launchd[1]
Oct 16 16:15:13 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent.Development): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:15:13 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.Plugin.32): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:15:13 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:15:13 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.Plugin.64): Unknown key for Boolean: _HighBitsASLR
Oct 16 16:15:16 Noahs-Macbook-Pro cloudd[867]: notify name "com.apple.cloudkit.pcs.flushCaches" has been registered 20 times - this may be a leak
Oct 16 16:15:32 Noahs-Macbook-Pro Spotlight[3374]: objc[3374]: __weak variable at 0x6000001073f0 holds 0x7fffa86203b9 instead of 0x600000195610. This is probably incorrect use of objc_storeWeak() and objc_loadWeak(). Break on objc_weak_error to debug.
Oct 16 16:15:32 Noahs-Macbook-Pro cloudd[867]: notify name "com.apple.cloudkit.pcs.flushCaches" has been registered 20 times - this may be a leak

SECOND CRASH:

Oct 16 16:15:38 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.Spotlight[3374]): Service exited due to signal: Illegal instruction: 4 sent by exc handler[0]
Oct 16 16:15:38 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.WebKit.Networking.5B42377E-B764-4A38-9155-F107E1E2EE31[3390]): Service exited with abnormal code: 1
Oct 16 16:15:38 Noahs-Macbook-Pro com.apple.xpc.launchd[1] (com.apple.ReportCrash[3403]): Endpoint has been activated through legacy launch(3) APIs. Please switch to XPC or bootstrap_check_in(): com.apple.ReportCrash

Has anyone seen this before and know how to fix it? (In case it's important, both of these computers have SIP turned off.)