Mutually exclusive development errors

Posted on 31/07/2008 by Alistair Hunt

The old ‘Mutex could not be created’ error

I have been doing some development in a new Visual Studio 2008 environment and was trying to debug my web service that I had created. As this was a new environment some of the security settings needed to be configured to allow me to run in DEBUG mode. After settings these permissons and starting my web service again I was still getting debug errors so I browsed the ASMX file from within IIS and got a ‘Mutex could not be created’ error within IE.

As with most of these errors I am not the first person to encounter the problem but I thought it was worth mentioning that this solution worked for me;

Close down all open Visual Studio IDE’s
Go to the ASP.NET Temporary folder for the version of the framework under which your application pool is running. For my web service running as a ASP.NET 2.0 application this is located at <%systemroot%>Microsoft.NetFrameworkv2.0.50727Temporary ASP.NET Files.
Delete the folder for your application.
Reset IIS
Check that you can now browse to your page, or web service, using IE.
Then reopen your solution within the development environment.

Problem solved! No more Mutex errors and I could debug my web service in my development enviroment. If you are interested, there is a useful Wikipedia article on Mutual Exclusion.

Vista still causing a few problems

Posted on 11/07/2008 by Alistair Hunt

The TMM Scheduled Task and Screen Refreshing on Vista

I have had a problem with my Vista Ultimate laptop when I have been using an external monitor which has been a pain for a while. Basically, when I unlocked my machine whilst it was connected to an external monitor, Vista would set the refresh rate of my external monitor to a value higher than the monitor was able to display. Consequently I would end up with a blank screen on my external monitor.

The simple fix has been to open the Display Settings (desk.cpl), choose my external monitor and then change the refresh rate back to a more sensible value. I can’t remember when this problem started with my desktop monitor but it was one of those things that, although anoying, I just put up with. Today I decided enough was enough and began the quest for a more definitive solution.

To cut a long story shorter, this seems to be working for me so far… http://www.revfry.com/2008/03/24/vista-and-screen-refreshing-at-unlock/. Thanks Rev.

I have persmission to do this…trust me!

Posted on 10/07/2008 by Alistair Hunt

Prompted for cedentials when accessing SharePoint library documents

At our office we have a number of MOSS 2007 document libraries. One of the issues I found with Vista is that it would constantly display the prompt for my credentials when I was trying to view any of these documents. I had already configured my Security Zones settings so that access to the document library was done through the Local Intranet zone including setting the automatic logon. Other people in the office using Windows XP were not experiencing the same issue.

After a few minutes surfing I came accross this Knowledge Base article that resolved my problem – http://support.microsoft.com/kb/943280 . The article explains the reasons for the problem so I won’t repeat it here however there are a couple of points worth highlighting;

If you have already installed Windows Vista SP1, which I did, then you do not need to download the hotfix, just apply the changes to the registry.
Once I had made the change to your registry I needed to reboot my machine in order for the change to be affective.

Needless to say, my issue was resolved and I am no longer getting prompted to provide my credentials when I access documents stored in our SharePoint document libraries.