Web.release.config transform error

I get the an error in deploy when Octopus applies the web.release.config transform.

Note that I am not concerned with the warnings. But the exception is the thing fails the deploy.

Info    14:56:06
Transforming 'e:\Octopus\Applications\MyEnv\MyApp\1000.0.0.2316_1\Web.config'.
Warning    14:56:06
(25:8) No element in the source document matches '/configuration/dataCacheClient/hosts/host[@name='localhost']'
Warning    14:56:06
(31:18) Argument 'debug' did not match any attributes
Error    14:56:06
Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.Web.XmlTransform.XmlTransformationLogger.LogWarning(XmlNode referenceNode, String message, Object[] messageArgs)
   at Microsoft.Web.XmlTransform.RemoveAttributes.Apply()
   at Microsoft.Web.XmlTransform.Transform.ApplyOnAllTargetNodes()
Fatal    14:56:06
One or more errors were encountered when applying the XML configuration transformation file: e:\Octopus\Applications\MyEnv\MyApp\1000.0.0.2316_1\Web.Release.config. View the deployment log for more details, or set the special variable Octopus.Action.Package.IgnoreConfigTranformationErrors to True to ignore this error.

Hi Chris,

Thanks for getting in touch. The null reference exception comes from deep within the configuration transformation code from Microsoft and there’s not much we can do about it. It’s actually directly caused by the warning about the missing ‘debug’ attribute - basically, it gets told to remove an attribute, but can’t find it, logs a warning, then attempts to remove it anyway and throws.

There are two things you can do:

  1. Fix the transform/config file so that the attribute does exist (thus no warning, and no error), or
  2. Create a variable called Octopus.Action.Package.IgnoreConfigTranformationErrors with a value of True to ignore the warnings and error.

Hope this helps!


After Octopus.Action.Package.IgnoreConfigTranformationErrors with a value of True is still throwing errors!!

You are right, that’s a bug (it suppresses most transform errors, but not exceptions thrown by the MS transformer). It will be fixed in 2.5.9.


Hi Paul,

Just want to confirm that the variable name, as implemented, includes the spelling error in Tranformation?

My first attempt at using this, I subconsciously fixed the error when typing, and it didn’t appear to work.

Hi Morgan,

Thanks for pointing that out! I have created a GitHub issue to add a new variable with the correct spelling, while also keeping the other so both will work.
You can track the issue here if you feel the need to update to the correct spelling once it’s done! https://github.com/OctopusDeploy/Issues/issues/1225