Biztalk: A failure occurred when executing a Windows service request.

A few days ago I received the following error while restarting the BizTalk host instances on one of the BizTalk servers here after an update.

I found the following in the event log:


I was pretty shocked about this and immediately tried with other host instances on the same machine.

All failed to start with the same error in the event log and a popup error which doesn’t reveal much:


I first thought there was an issue with an underlying service (ESSO or SQL) but all of them were happily running and working fine it seemed.

Finally this forum post gave me a glimpse on what might be wrong. Someone mentions:
“Check out the configuration file for the 64-bit to ensure there are no custom entries. Let me know.”

Indeed, I had adapted the BTSNTSvc.exe.config and BTSNTSvc64.exe.config files with some custom appSettings entries.

The entry I added was something like this:

<add key=”Link” value=”http://server/site/page.aspx?page=1&Id={0}”/>

I renamed the file to have an xml extension to see if it would validate in IE and it did. So it seemed to be valid XML.

Knowing that the ampersand (&) sign can cause some issues in XML I removed it and saved the file.
Indeed, the host instances started without an issue now…

So I escaped the character like this:

<add key=”Link” value=”http://server/site/page.aspx?page=1&amp;Id={0}”/>

And now the hosts have no issue starting up again!

I hope this helps someone, because I did not find a blog post anywhere about this fairly common issue it seems.
Leave a message if it does!