Ah, but it does run under 4.0...
Do you see anything strange in the web.config? Follows:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<sectionGroup name="system.web">
<section name="galleryServerPro" type="GalleryServerPro.Configuration.GalleryServerProConfigSettings, GalleryServerPro.Configuration" allowDefinition="MachineToApplication" restartOnExternalChanges="true" requirePermission="false" />
</sectionGroup>
<section name="cachingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Caching.Configuration.CacheManagerSettings, Microsoft.Practices.EnterpriseLibrary.Caching" requirePermission="false" />
</configSections>
<connectionStrings>
<clear />
<add name="ADConnection" connectionString="LDAP://SERVERNAME/CN=Users,DC=DOMAIN,DC=COM" />
<add name="SQLiteDbConnection" connectionString="Data Source=|DataDirectory|galleryserverpro_data.sqlite;Version=3;" />
<add name="SqlServerDbConnection" connectionString="server=SERVERNAME\SQLEXPRESS;uid=gsp_owner;pwd=PASSWORD;Trusted_Connection=no;database=GalleryServerPro;Application Name=Gallery Server Pro" />
</connectionStrings>
<appSettings>
<add key="ComponentArtScriptControls" value="PerControl" />
</appSettings>
<cachingConfiguration defaultCacheManager="Cache Manager">
<cacheManagers>
<add expirationPollFrequencyInSeconds="60" maximumElementsInCacheBeforeScavenging="1000" numberToRemoveWhenScavenging="10" backingStoreName="Null Storage" name="Cache Manager" />
</cacheManagers>
<backingStores>
<add encryptionProviderName="" type="Microsoft.Practices.EnterpriseLibrary.Caching.BackingStoreImplementations.NullBackingStore, Microsoft.Practices.EnterpriseLibrary.Caching" name="Null Storage" />
</backingStores>
</cachingConfiguration>
<system.web>
<pages theme="" styleSheetTheme="" validateRequest="false" controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"></pages>
<galleryServerPro configSource="gs\config\galleryserverpro.config" />
<!-- <trust level="Full" /> -->
<globalization uiCulture="auto:en" culture="auto:en-US" />
<xhtmlConformance mode="Strict" />
<compilation debug="false" targetFramework="4.0">
<assemblies>
<add assembly="System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
<add assembly="System.Web.Extensions.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
</assemblies>
</compilation>
<!-- The <authentication> section enables configuration of the security authentication mode used by
ASP.NET to identify an incoming user.
The timeout is set to 129,600 minutes by default, which is 90 days. This allows the user to be automatically
logged in (requires selecting the "Remember Me" checkbox during login which sets a persistent cookie).
Note that when the user clicks "Log out", the persistent cookie is removed and the user will have to
log in next time. -->
<authentication mode="Forms">
<forms protection="All" timeout="129600" slidingExpiration="true" />
</authentication>
<authorization>
<!-- <deny users="?" />-->
</authorization>
<!-- Configure the Membership provider.-->
<membership defaultProvider="AspNetActiveDirectoryMembershipProvider">
<providers>
<clear />
<add name="AspNetActiveDirectoryMembershipProvider" type="System.Web.Security.ActiveDirectoryMembershipProvider, System.Web,Version=2.0.0.0,Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a"
connectionStringName="ADConnection" enableSearchMethods="true"/>
</providers>
</membership>
<!-- Configure the Role provider.-->
<roleManager enabled="true" cacheRolesInCookie="true" cookieProtection="Validation" defaultProvider="SqlRoleProvider">
<providers>
<clear />
<add applicationName="Gallery Server Pro" connectionStringName="SqlServerDbConnection" name="SqlRoleProvider" type="System.Web.Security.SqlRoleProvider" />
</providers>
</roleManager>
<!-- Configure the Profile provider.-->
<profile defaultProvider="SqlProfileProvider">
<providers>
<clear />
<add applicationName="Gallery Server Pro" connectionStringName="SqlServerDbConnection" name="SqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" />
</providers>
<properties>
<add name="ShowMediaObjectMetadata" defaultValue="false" type="String" allowAnonymous="false" />
<add name="UserAlbumId" defaultValue="0" type="Int32" allowAnonymous="false" />
<add name="EnableUserAlbum" defaultValue="true" type="String" allowAnonymous="false" />
</properties>
</profile>
<httpHandlers>
<add verb="*" path="ComponentArtUploadProgress.axd" type="ComponentArt.Web.UI.UploadProgressHandler, ComponentArt.Web.UI" />
<add verb="*" path="ComponentArtScript.axd" type="ComponentArt.Web.UI.ScriptHandler,ComponentArt.Web.UI" />
</httpHandlers>
<httpModules>
<add name="ComponentArtUploadModule" type="ComponentArt.Web.UI.UploadModule, ComponentArt.Web.UI" />
</httpModules>
<sessionState mode="InProc" timeout="60" />
<!-- The <customErrors> section controls what happens if/when an unhandled error occurs. This setting is
ignored if enableExceptionHandler=true in galleryserverpro.config.
The mode attribute must be one of these values: Off (No redirection is performed; all users get detailed
error message), On (all users are redirected to friendly error page), RemoteOnly (local users see detailed
error message, remote users are redirected) -->
<customErrors mode="RemoteOnly" />
</system.web>
<!--
The site admin page lets you specify the smtp server and port, and the entries are stored in galleryserverpro.config.
If you need to specify a username and password, you can do so here. When this section is configured, the smtp
server and port in galleryserverpro.config are ignored, so make sure to include the server and port here. Uncomment
the section below to make it take effect. -->
<!--
<system.net>
<mailSettings>
<smtp>
<network
host="relayServerHostname"
port="portNumber"
userName="username"
password="password" />
</smtp>
</mailSettings>
</system.net>
-->
<!-- By default ASP.NET prevents file uploads larger than 4 MB. To change this, increase the maxRequestLength
attribute for all pages that host the Gallery Server Pro user control. Ex: To allow files up to 2 GB, use
maxRequestLength="2097151". This value should be the same or higher than the maxUploadSize setting in
galleryserverpro.config (which is exposed on the Site admin - Media objects - General page). The maxUploadSize
setting is the preferred way to manage upload sizes, as GSP provides a friendly message when that value is
violated, which is not possible when maxRequestLength is violated.
It is also recommended to increase the timeout from the default value
of 90 seconds to allow for long-running tasks such as file uploads. Set the
executionTimeout attribute to the desired value (8 hours = 28800, 24 hrs = 86400). -->
<location path="default.aspx">
<system.web>
<httpRuntime maxRequestLength="2097151" executionTimeout="86400" />
</system.web>
</location>
<system.web.extensions>
<scripting>
<webServices>
<jsonSerialization maxJsonLength="2147483647" />
</webServices>
<scriptResourceHandler enableCompression="true" enableCaching="true" />
</scripting>
</system.web.extensions>
<system.webServer>
<!-- By default IIS 7 restricts uploads larger than about 30 MB. To allow larger uploads, use the <requestFiltering>
element to set a new value. The attribute maxAllowedContentLength is in bytes, so to set a new value of 2 GB,
use 2147483648 (2 * 1024 * 1024 * 1024).
Note: If you get an error that requestFiltering cannot be overriden you must edit
%windir%\System32\inetsrv\config\applicationHost.config file and change the string:
<section name="requestFiltering" overrideModeDefault="Deny" />
to:
<section name="requestFiltering" overrideModeDefault="Allow" />
-->
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="2147483648"/>
</requestFiltering>
</security>
<validation validateIntegratedModeConfiguration="false" />
<modules>
<remove name="ComponentArtUploadModule" />
<add name="ComponentArtUploadModule" type="ComponentArt.Web.UI.UploadModule, ComponentArt.Web.UI" />
</modules>
<handlers>
<remove name="ComponentArtUpload" />
<remove name="ComponentArtScriptHandler" />
<add name="ComponentArtUpload" path="ComponentArtUploadProgress.axd" type="ComponentArt.Web.UI.UploadProgressHandler, ComponentArt.Web.UI" verb="*" />
<add name="ComponentArtScriptHandler" path="ComponentArtScript.axd" type="ComponentArt.Web.UI.ScriptHandler,ComponentArt.Web.UI" verb="*" />
</handlers>
<defaultDocument>
<files>
<remove value="default.aspx" />
<add value="default.aspx" />
</files>
</defaultDocument>
</system.webServer>
</configuration>