Where are the log files

Sometimes, many times, with errors it is best to know how to reproduce the error, then cause the error at a specific known time. So immediately after a specific minute mark so you can then look in the first 3 or 4 seconds of the log for that minute.

Logs may use server local time or UTC time depending, it is usually fairly easy to tell - create the error, then find the last log file, the times there should tell you quickly which HOUR you want, and then you look back and find the minute.

MCe

ALL versions: Where MCe is installed

In a 'log' directory.

MC

Newer (2025) versions has a bit of logs in the IIS directory that MC is in

IIS

We only support modern versions of IIS but in case you are finding links on the internet, note that IIS 6 and earlier stored them in the Windows Directory not the inetpub as below

IIS 7 and later: %SystemDrive%\inetpub\logs\LogFiles
IIS 6 and earlier: %WinDir%\System32\LogFiles

Log type	Default path
Site access logs (W3C)	C:\inetpub\logs\LogFiles\W3SVC<siteID>\u_ex*.log
Default Web Site logs	C:\inetpub\logs\LogFiles\W3SVC1\
HTTP.sys / kernel errors	C:\Windows\System32\LogFiles\HTTPERR\httperr*.log
Failed Request Tracing (FREB)	C:\inetpub\logs\FailedReqLogFiles\W3SVC<siteID>\
ASP.NET / app events	Windows Event Viewer → Application log
IIS service events	Windows Event Viewer → System log
Logging config (per site)	%windir%\system32\inetsrv\config\applicationHost.config

The log filename encodes the date and the rollover period: u_ex = W3C UTC daily, u_ex270603.log = the log for 2027.06.03. Hourly rollover produces u_exYYMMDDHH.log. So to be clear u_ex200602 is not from 2006, it is is from 2020.06.02 at least for the next 70 years or so