once upon a time Acumatica requires for certified developers to pass over certification again.
As obedient person I decided to install T100 sample application over Acumatica Framework Configuration ( don't mix with Acumatica ERP Configuration ). Then I navigated to just installed application, and here is what I've seen:
Server Error in '/T100a' Application.
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: The connection string name is missing for the MySqlSiteMapProvider
Line 283: <siteMap>
Line 284: <providers>
Line 285: <add name="MySqlSiteMapProvider" type="MySql.Web.SiteMap.MySqlSiteMapProvider, MySql.Web, Version=184.108.40.206, Culture=neutral, PublicKeyToken=c5687fc88969c44d" connectionStringName="LocalMySqlServer" applicationName="/" />
Line 286: </providers>
Line 287: </siteMap>
Source File: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config Line: 285
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.3282.0
Very puzzling honestly speaking. You've just installed something, and right from the start it doesn't work.
After some Research I have found, that following some additions should be added to node siteMap section providers:
<siteMap enabled="true" defaultProvider="PXDatabaseSiteMapProvider">
<remove name="MySqlSiteMapProvider" /> <!-- add this line -->
<remove name="PXWikiProvider" />
After those additions I was able to open Training sample T100.