Tag Archives: IIS

CSS, Javascript, Images cause 500 errors after IIS Website upgrade

Symptoms

A website has been copied from a server running IIS 6 (Windows Server 2008) to a server running IIS 10 (Windows Server 2019). Pages do not render correctly, and further investigation shows that pictures, css files, and javascript are all failing with 500 (Internal Server Error) responses. This is shown here in the F12 view in Chrome.

 2020-02-13_11-18-38

Trying to access one of these static files directly also fails and just shows the message “The page cannot be displayed because an internal server error has occurred.

2020-02-13_11-17-35

Cause

In my case, the site was referencing the FontAwesome package which uses the WOFF file type. In the older IIS this MIME type was not registered so required a manual entry in the configuration. In the newer IIS this is handled natively and the manual configuration is now causing a problem rather than remediating one.

Solution

Check the web.config file for a reference to “woff” for example

<mimeMap fileExtension=”.woff” mimetype=”application/font-woff” />

and comment out or remove this line.

2020-02-13_11-20-07

Refresh the page in your browser and it should now load correctly.

Microsoft.Jet.OLEDB.4.0 provider is not registered on the local machine

I’ve come across this error a couple of times in the past few weeks when migrating old ASP.NET websites to new web servers so I’m popping it into the blog as an aide-memoire for myself and in case it’s useful for others.

The error message below (“Server Error in … Application”, “The Microsoft.Jet.OLEDB.4.0 provider is not registered on the local machine) pops up when trying to open a page which uses the database (in this case a Microsoft Access DB).

2017-06-16

The fix is to enable 32-bit applications for the relevant Application Pool using Internet Information Services Manager.  The Jet drivers are not 64-bit, and by default IIS8 (Server 2012R2) has 32-bit apps disabled.

  1. Open IIS Manager
  2. Navigate to the Application Pools Node underneath the web server.
  3. Select the App Pool in question. If in doubt look at the “Applications” column, if only one has any applications in it then that’s the one you want 🙂
  4. On the Actions menu on the right-hand side click on “Advanced Settings”
  5. In the “Advanced Settings” dialog set the value of “Enable 32-Bit Applications” to True and click OK.

2017-06-16 (1)