Welcome to Stephen's wiki. There is lots of really great content here - you just have to search for it.

This is a collection of random stuff I want to record for future reference. Probably not much use to anyone else.

ASP.NET's UpdatePanel will not work if xhtmlConformance mode is set to Legacy in the Web.config file:

<xhtmlConformance mode="Legacy" />

Take it out of the Web.config file - it almost certainly does not need to be in there.

With administrator privileges, edit the C:\Program Files (x86)\VideoLAN\VLC\lua\http\.hosts file, and set it to:

::/0
0.0.0.0/0

This will probably need to be done every time a new version of VLC is installed.

Probably caused by the Web.config file. Remove the following, if they exist:

<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
 
<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere" />
<section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication" />
<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication" />
<section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication" />

Removing these from the Web.config doesn't seem to matter, but if it does, try adding the relevant DLL files and see if that fixes the problem.