Question: I am trying to remove the little color marks in my Visual Studio code window by applying the VS hints, but these are apparentely impossible because these cause build errors. Here is my simplified code:

```
using System.Xml.Linq;

XDocument XReport = new XDocument(new XDeclaration("1.0", "utf-8", "yes"));
XProcessingInstruction XI = ... ;//ref to xsl stylesheet
XReport.Add(XI);
XReport.Add(...more xml content...);
string NewPageContent = XReport.Declaration.ToString() + XReport.ToString();

```

Here is a screenshot when my mouse hovers over the wavy line under ToString:

![screenshot of the VS hints](https://i.stack.imgur.com/KHAh1.jpg)

This code runs just fine, but VS hints that I should remove the `.ToString()` twice, then the code builds with an error that you cannot add an `XReport.Declaration` and an `XReport`, which makes sense.

Is this a known VS bug?

Any comments on making my code better is also appreciated.

Answer: 
This is not a Visual Studio thing, it is a [DevExpress](https://www.devexpress.com/Products/CodeRush/refactor_pro.xml) add-in showing you this message.

The message is wrong, period. The `+` operator is invalid on those objects, and if they did implement the `+` operator, it would be unlikely to result in a `string`.

Report the bug at DevExpress.
Of course this not a bug but a feature :-)

We can remove either one of the `.ToString()` calls, but not both, and it will build ok! So the two hints are correct.

The new bug is that after removing one call, the other still has the wavy line, but cannot be removed.

I do not know the syntax details here, but if it builds, I guess it's ok.

(actually, I don't know if this qualifies as an answer)