The "EnsureBindingRedirects" task failed unexpectedly

I had this error but slightly different, took me 45 minutes to figure it out so thought I'd better get this out there.

Was experiencing the "EnsureBindingRedirects" task failed unexpectedly problem but mine came from an XmlException:

(...)\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets(97,5): error MSB4018: System.Xml.XmlException: '=' is an unexpected token. The expected token is ';'. Line 39, position 175.

Turns out the cause was that I'd recently added an entry to my web.config's appSettings where the value was a URL that contained an ampersand (&).

Ampersands need to be escaped in XML, even in attribute values.

I changed all the & in the URL value to & and it built without issue.

It's a bug in Microsoft.Bcl.Build and to solve it you have to put culture info in the assemblyIdentity-part of web.config or app.config.

For example if you have:

<dependentAssembly>
   <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
   <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
</dependentAssembly>

change it to:

<dependentAssembly>
    <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
</dependentAssembly>