I am using the SDL Template Builder 7.1 (build 7.1.0.114).

The template builder worked correctly for a long time but now I am getting the following error by every template I try to debug:

> System.Web.Services.Protocols.SoapException: Type
> System.Runtime.Remoting.ObjRef and the types derived from it (such as
> System.Runtime.Remoting.ObjRef) are not permitted to be deserialized
> at this security level.
> 
>    at
> System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage
> message, WebResponse response, Stream responseStream, Boolean
> asyncCall)    at
> System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String
> methodName, Object[] parameters)    at
> Tridion.ContentManager.Templating.CompoundTemplates.DomainModel.Proxy.CompoundTemplateWebService.StartDebuggingWithItemUri(String
> compoundTemplateId, String compoundTemplateXml, String itemId, Boolean
> includeSystemLog, TraceEventType logLevel)    at
> Tridion.ContentManager.Templating.CompoundTemplates.DomainModel.DebugObject.Start(Template
> template, Object debugItem, LoggingOptions loggingOptions)

**What I already tried:**

- I tried the 'Log on As...' option but that didn't help.

- I checked some other StackExchange posts but couldn't find the same situation.

- I added the following section to the web.config in Tridion/templating directory (after a suggestion of Nuno)

[![template builder web.config][1]][1]

Thanks in advance!


  [1]: https://i.sstatic.net/f6EoT.png