After setting a machine key inside my web.config, I got the following IIS error:
Decryption key specified has invalid hex characters
Here is the related web.config line:
<machineKey decryptionKey="decription key is here" validation="SHA1" validationKey="validationkey,IsolateApps" />
The root cause of this error is that in fact the configuration I specified above is invalid. Using an explicit decryptionKey together with the IsolateApps modifier doesn’t work. The IsolateApps
modifier causes ASP.NET to generate a unique key for each application on your server. This is only applicable if you are getting ASP.NET to auto-generate keys at runtime.
More information: https://stackoverflow.com/questions/15002960/isolateapps-causes-decryption-key-specified-has-invalid-hex-characters