Category Archives: Tony Phillips

Troubleshooting Office Web App Farm Installations

New functionality in Microsoft Office Web Apps is the preview feature in search (see below). Setting up a separate farm for Office Web Apps is a great way to improve performance and make a scalable solution but it can bring up some new technical challenges. A couple of the most common issues are listed below.

Web Apps Search Preview

Do the internal and external URLs of the Web Apps Server resolve from the SharePoint server?

Should return XML without certificate error

Should return XML without certificate error

Certificate Error?

When setting up the web apps farm, a SAN certificate needs to be specified with both the internal URL and the external URL (see below). Wildcard or single host certificates will not work.

SAN Certificate
404 not found?

Both the SharePoint and Web App server need to see each other. Make sure that internal DNS is setup for the external web app address. Run ipconfig /flushdns on the SharePoint server. The SharePoint server needs to resolve both addresses internally.

The Web Apps server also needs to have an entry for the SharePoint site URL. Ensure that the SharePoint site has an internal DNS entry and flush the DNS on the web apps server. Browse to the SharePoint site on the web apps server to ensure that it can see the site without any certificate errors.

How to enable blob cache for SharePoint 2013 image renditions

One of the new features of SharePoint 2013 is the image renditions. When configuring this you may find the following error:

The blob cache is not enabled in this web application. Image renditions will not be generated until the blob cache is enabled. For information on turning on the blob cache, please review the product documentation.

Image Renditions Error SharePoint 2013


Open the web.config file for the web application in a text editor. Search for “blobcache location”.

Inside this tag, change the “enabled” attribute from false to true (see below). This will enable blob cache on the server to enable SharePoint 2013 image renditions.

<BlobCache location="C:\BlobCache\14" path="\.(gif|jpg|jpeg|jpe|jfif|bmp|dib|tif|tiff|themedbmp|themedcss|themedgif|themedjpg|themedpng|ico|png|wdp|hdp|css|js|asf|avi|flv|m4v|mov|mp3|mp4|mpeg|mpg|rm|rmvb|wma|wmv|ogg|ogv|oga|webm|xap)$" maxSize="10" enabled="true" />

Save the web.config file and refresh your browser page. All sorted!

Image Rendition Working in SharePoint 2013