I've actually got the same problem. I get the following error:
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Installing SilverStripe...
I am now running through the installation steps (this should take about 30 seconds)
If you receive a fatal error, refresh this page to continue the installation
# Creating 'mysite/_config.php'...
# Creating '.htaccess' file...
# Building database schema...
Notice: Warning: there are two 'Extension' files with the same filename: '/home/domain/sapphire/core/Extension.php' and '/home/domain/auth_openid/code/Auth/OpenID/Extension.php'. This might mean that the wrong code is being used. in /home/.capreesch/domain/sapphire/core/ManifestBuilder.php on line 246
Notice: Warning: there are two 'XML' files with the same filename: '/home/domain/sapphire/integration/XML.php' and '/home/domain/auth_openid/code/Auth/Yadis/XML.php'. This might mean that the wrong code is being used. in /home/.capreesch/domain/sapphire/core/ManifestBuilder.php on line 246
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I did a fresh install so don't see how a duplicate file could have been caused. Do I simply delete the duplicate files in /Auth/... ?