1. PHP 8.1.8
2. Go to http://phorge.localhost/auth (`Login and Registration Providers`)
3. Select {nav icon=commenting, name=Customize Messages} in the sidebar to go to http://phorge.localhost/auth/message/
4. Have no previous message customizations performed on this instance
5. Select first item `Username Change Instructions` to go to http://phorge.localhost/auth/message/user.edit.username/ or second item; get stacktraces 2 and 3 below.
5. Select third item (`Mail Body: Set Password`) to seventh item `Mail Body: Welcome`; , get stacktraces 1 and 2 and 3 below.
```
[2023-05-01 21:33:59] EXCEPTION: (RuntimeException) strlen(): Passing null to parameter #1 ($string) of type string is deprecated at [<arcanist>/src/error/PhutilErrorHandler.php:261]
arcanist(head=T15263, ref.master=82d1abd4edd1, ref.T15263=4324d11c8b49), phorge(head=T15325, ref.master=8f669ea08289, ref.T15325=bac8bc45a980)
#0 <#2> PhutilErrorHandler::handleError(integer, string, string, integer) called at [<phorge>/src/applications/auth/controller/message/PhabricatorAuthMessageViewController.php:106]
#1 <#2> PhabricatorAuthMessageViewController::buildPropertiesView(PhabricatorAuthMessage) called at [<phorge>/src/applications/auth/controller/message/PhabricatorAuthMessageViewController.php:56]
#2 <#2> PhabricatorAuthMessageViewController::handleRequest(AphrontRequest) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:284]
#3 phlog(RuntimeException) called at [<phorge>/src/aphront/handler/PhabricatorDefaultRequestExceptionHandler.php:41]
#4 PhabricatorDefaultRequestExceptionHandler::handleRequestThrowable(AphrontRequest, RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:751]
#5 AphrontApplicationConfiguration::handleThrowable(RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:296]
#6 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink, MultimeterControl) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:204]
#7 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phorge>/webroot/index.php:35]
```
Fix that line, get next exception:
```
[2023-05-01 21:27:35] EXCEPTION: (RuntimeException) strlen(): Passing null to parameter #1 ($string) of type string is deprecated at [<arcanist>/src/error/PhutilErrorHandler.php:261]
arcanist(head=T15263, ref.master=82d1abd4edd1, ref.T15263=4324d11c8b49), phorge(head=T15325, ref.master=8f669ea08289, ref.T15325=8f669ea08289)
#0 <#2> PhutilErrorHandler::handleError(integer, string, string, integer) called at [<phorge>/src/applications/auth/controller/message/PhabricatorAuthMessageViewController.php:114]
#1 <#2> PhabricatorAuthMessageViewController::buildPropertiesView(PhabricatorAuthMessage) called at [<phorge>/src/applications/auth/controller/message/PhabricatorAuthMessageViewController.php:56]
#2 <#2> PhabricatorAuthMessageViewController::handleRequest(AphrontRequest) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:284]
#3 phlog(RuntimeException) called at [<phorge>/src/aphront/handler/PhabricatorDefaultRequestExceptionHandler.php:41]
#4 PhabricatorDefaultRequestExceptionHandler::handleRequestThrowable(AphrontRequest, RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:751]
#5 AphrontApplicationConfiguration::handleThrowable(RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:296]
#6 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink, MultimeterControl) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:204]
#7 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phorge>/webroot/index.php:35]
```
Fix that line, get next exception:
```
[2023-05-01 21:29:09] EXCEPTION: (RuntimeException) strlen(): Passing null to parameter #1 ($string) of type string is deprecated at [<arcanist>/src/error/PhutilErrorHandler.php:261]
arcanist(head=T15263, ref.master=82d1abd4edd1, ref.T15263=4324d11c8b49), phorge(head=T15325, ref.master=8f669ea08289, ref.T15325=8f669ea08289)
#0 <#2> PhutilErrorHandler::handleError(integer, string, string, integer) called at [<phorge>/src/applications/auth/controller/message/PhabricatorAuthMessageViewController.php:123]
#1 <#2> PhabricatorAuthMessageViewController::buildPropertiesView(PhabricatorAuthMessage) called at [<phorge>/src/applications/auth/controller/message/PhabricatorAuthMessageViewController.php:56]
#2 <#2> PhabricatorAuthMessageViewController::handleRequest(AphrontRequest) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:284]
#3 phlog(RuntimeException) called at [<phorge>/src/aphront/handler/PhabricatorDefaultRequestExceptionHandler.php:41]
#4 PhabricatorDefaultRequestExceptionHandler::handleRequestThrowable(AphrontRequest, RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:751]
#5 AphrontApplicationConfiguration::handleThrowable(RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:296]
#6 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink, MultimeterControl) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:204]
#7 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phorge>/webroot/index.php:35]
```
Fix that line. Afterwards, page `Username Change Instructions` at http://phorge.localhost/auth/message/user.edit.username/ gets rendered in web browser.