Hi all,
I'm getting a little desesperate with this update.
I have a Windows Server 2008 Standard with SQL 2008 and Plesk.
It runs a few websites and one of them had the DotNetNuke 4.8. I had the need to update to 4.9 because of the bug when using TextEditor and PartialRendering, and everything fall apart.
I keep getting this error:
Server Error in '/' Application.
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Security Exception
Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file.
Exception Details: System.Security.SecurityException: Request for the permission of type 'System.Web.AspNetHostingPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace:
[SecurityException: Request for the permission of type 'System.Web.AspNetHostingPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.]
System.RuntimeTypeHandle._GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, Boolean loadTypeFromPartialName) +0
System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) +64
System.RuntimeType.PrivateGetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) +58
System.Type.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +65
System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +342
System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +52
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Version Information: Microsoft .NET Framework Version:2.0.50727.3053; ASP.NET Version:2.0.50727.3053
I am running the app in Full Trust and did all the changes I was supposed in the web.config.
The weirdest thing is that if I overwrite the directory again with the backuped 4.8 version, it works like a charm.
If I place the 4.9 upgrade package again and overwrite the files it falls apart and I only get this enervating error!!
Can anyone help me please, I'm been in this for the past 12 hours... 
I really appreciate all the help you can give me!
Thanks in advance!
João Pereira