Still having the same problems, and the exceptions are still totally random. About one in five clicks on the site, no matter what, gives a security exception, and it is entirely out of the question for the web site to do this once it goes live... mine is hosted by 1and1 Internet as well...

Would it help anything if I changed the security level to High? It's a church web site with limited membership, not a high-profile public site that needs to be totally secure...

One thing I failed to do when installing DNN 4.0.3 was notice the following paragraph in the Installation Guide: -

As with v3.x, before doing anything else rename release.config to web.config (if you

are required to run under Medium Trust then rather than use release.config, rename

development.config).

I used the release.config because I wasn't aware at the time that 1&1 are running under Medium Trust. However, as far as I can see the release.config does have the medium trust support entries in it at the top of the file. Is there something else in the development.config that I'm missing and, if there is, is there any way that I can recover the situation without having to re-install??

It is asp.net security policy issue! Go to web.config change the node into this:

 

<trust level="High" originUrl="http://localhost/.*"/>