Automatic shutdowns of Macbook Pro?

Thank you for your help! I tried to follow your advice, but I can't seem to locate log entries by time. After I got to Utilities, I looked in the "Activity Monitor" folder -- is that the right one? It does seem to have activity, but no time stamps. Am I doing something wrong? Thank you again!

Thank you for the help. The sudden shutdowns appear to have stopped. The last one was the morning that I rebooted. It immediately shut down, before I even opened any applications or documents. I looked at the logs, but I'm not really sure what is "suspicious" and what is a normal operating error. I saw the following message several times:

3/18/16 8:10:12.475 AM ReportPanic[408]: Failed to connect (panicHeaderLabel) outlet from (ReportPanicAppDelegate) to (NSTextField): missing setter or instance variable

3/18/16 8:10:12.475 AM ReportPanic[408]: Failed to connect (panicMessageLabel) outlet from (ReportPanicAppDelegate) to (NSTextField): missing setter or instance variable

3/18/16 8:10:12.475 AM ReportPanic[408]: Failed to connect (reportButton) outlet from (ReportPanicAppDelegate) to (NSButton): missing setter or instance variable

3/18/16 8:10:12.478 AM ReportPanic[408]: ReportPanic could not stat /Library/Logs/DiagnosticReports/Kernel_2016-03-17-XXXXX_Katherines-MacBook-Pro. panic

3/18/16 8:10:12.567 AM pboard[416]: Attempt to unlink previous shared memory during startup returned an error. Continuing...

A little further down was the following:

3/18/16 8:10:28.726 AM com.apple.internetaccounts[485]: Adding listener

3/18/16 8:10:28.959 AM NotificationCenter[458]: Layout still needs update after calling -[NSView layout]. NSView or one of its superclasses may have overridden -layout without calling super. Or, something may have dirtied layout in the middle of updating it. Both are programming errors in Cocoa Autolayout. The former is pretty likely to arise if some pre-Cocoa Autolayout class had a method called layout, but it should be fixed.

3/18/16 8:10:28.987 AM identityservicesd[444]: <IMMacNotificationCenterManager: [number]>: Configuring notification center for identifier: com.apple.iChat topics: (

)

3/18/16 8:10:29.011 AM identityservicesd[444]: <IMMacNotificationCenterManager: [number]>: NC Disabled: NO

3/18/16 8:10:29.018 AM identityservicesd[444]: <IMMacNotificationCenterManager: [number]>: DND Enabled: NO

3/18/16 8:10:29.018 AM storeaccountd[492]: AccountServiceDelegate: Accepting new connection <NSXPCConnection: [DELETED BY RESEARCHADDICT> connection from pid 458 with interface <AccountServiceInterface: DELETED BY RESEARCHADDICT> (PID 458)

3/18/16 8:10:29.018 AM identityservicesd[444]: <IMMacNotificationCenterManager: DELETED BY RESEARCHADDICT>: Updating enabled: YES (Topics: (

))

3/18/16 8:10:29.133 AM SystemUIServer[427]: Cannot find executable for CFBundle [number] </System/Library/CoreServices/Menu Extras/Clock.menu> (not loaded)

3/18/16 8:10:29.151 AM SystemUIServer[427]: Cannot find executable for CFBundle [number] </System/Library/CoreServices/Menu Extras/Volume.menu> (not loaded)

3/18/16 8:10:29.172 AM SystemUIServer[427]: *** WARNING: Method convertRectToBase: in class NSView is deprecated on 10.7 and later. It should not be used in new applications.

3/18/16 8:10:29.172 AM SystemUIServer[427]: *** WARNING: Method convertRectFromBase: in class NSView is deprecated on 10.7 and later. It should not be used in new applications.

3/18/16 8:10:29.272 AM Keychain Circle Notification[455]: rawStatus 1, #applicants 0, #peers 5, err=(null)

If more information would be helpful, I can add it. The log was pretty long, and I wasn't sure that any of it would be helpful. I have no idea why it has stopped shutting down, but I hope that's a good sign... Thank you for all of your help!

Yosemite. 10.10.5

I don't seem to have a file called "PanicReporter" under my /Library/Logs/" I have "CrashReporter". There was only one line under that, which didn't seem particularly useful (but then, I'm not sure I'm the best judge of that). I ran a search for the word "panic," and the following came up:

3/18/16 8:10:12.475 AM ReportPanic[408]: Failed to connect (panicHeaderLabel) outlet from (ReportPanicAppDelegate) to (NSTextField): missing setter or instance variable

3/18/16 8:10:12.475 AM ReportPanic[408]: Failed to connect (panicMessageLabel) outlet from (ReportPanicAppDelegate) to (NSTextField): missing setter or instance variable

3/18/16 8:10:12.475 AM ReportPanic[408]: Failed to connect (reportButton) outlet from (ReportPanicAppDelegate) to (NSButton): missing setter or instance variable

3/18/16 8:10:12.478 AM ReportPanic[408]: ReportPanic could not stat /Library/Logs/DiagnosticReports/Kernel_2016-03-17-XXXXXX_Katherines-MacBook-Pro .panic

3/22/16 5:12:17.766 PM ReportPanic[210]: Failed to connect (panicHeaderLabel) outlet from (ReportPanicAppDelegate) to (NSTextField): missing setter or instance variable

3/22/16 5:12:17.766 PM ReportPanic[210]: Failed to connect (panicMessageLabel) outlet from (ReportPanicAppDelegate) to (NSTextField): missing setter or instance variable

3/22/16 5:12:17.767 PM ReportPanic[210]: Failed to connect (reportButton) outlet from (ReportPanicAppDelegate) to (NSButton): missing setter or instance variable

3/22/16 5:12:17.770 PM ReportPanic[210]: ReportPanic could not stat /Library/Logs/DiagnosticReports/Kernel_2016-03-17-XXXXXX_Katherines-MacBook-Pro .panic

This information doesn't cover all of the shutdowns, because I've had at least 4 of those... maybe 6 or so that I've observed. I didn't notice the shutdown on 3/22/16 that is noted above. I thought that they had stopped by that point. I wonder if there are issues with my use of hotmail as an e-mail account. I get notices of problems on that website frequently, telling me to reload. Is it possible that the site is incompatible with Macs?