Fix: "A Microsoft SharePoint Foundation compatible application could not be found to edit this document."

You get the following error when trying to open a document stored on SharePoint in Microsoft Office 2010:

"The document could not be opened for editing.  A Microsoft SharePoint Foundation compatible application could not be found to edit the document."

Here are some things to check:

• Internet Explorer is recommended for best compatibility.  However if you’re using Firefox, there are some steps you can take as outlined in KB979634.
• Make sure you’re using 32 bit Internet Explorer.
• Verify the Internet Explorer Add-on “SharePoint OpenDocuments Class” is installed and enabled (be sure to Show All add-ons).  If it’s not installed, do a repair install of Office and check again.

8/26/2013 Addendum:
Thought I'd update with what I've found for Office 2013, but not tried at this point.  See this msdn forum:

• Office 2013 June CU (link)
• Registry changes to add a US local key as mentioned in the forum linked above.

Looback errors on SharePoint server

While testing a migration from one SharePoint server to another I was noticing several various errors that may all be attributed to the same problem.  The underlying configuration is the default zone URL is a dns alias.  Errors:

• Nintex Workflow returns "Error returned from server: The remote server returned an error: (401) Unauthorized."  The workflow is starting another workflow which saves attachments on a list item to a document library.
• In the IIS log there are several 401 errors at the time of the workflow but no username.
• The SharePoint Server Search has error ID 14 in the event log which is the SharePoint URL cannot be crawled.  The same errors can be found in the Crawl History for the Search Service Application (Central Admin --> Application Management --> Manage Service Applications).

After creating and setting the registry key DisableLoopbackCheck (DWORD) = 1 at HKLM\SYSTEM\CurrentControlSet\Control\Lsa\ (see Microsoft Support Article 926642 for specific steps):

• Search no longer errors trying to access the local SharePoint sites (there are errors trying to access specific files).
• Workflow does not error when trying to call the second workflow.

SharePoint Unexpected Error with Correlation ID

There are many places in SharePoint where the descriptive error message: "An unexpected error has occured" shows up in the browser along with a Correlation ID.  Checked the server's event log shows nothing.  Not even an "unexpected error" message.

I found this Microsoft blog post about using the correlation id:
http://sharepoint.microsoft.com/Blogs/GetThePoint/Lists/Posts/Post.aspx?ID=353.  It's a complicated post, but if you're comfortable with Excel you might choose to use it.  A perhaps friendlier solution is to use the ULS Viewer available from MSDN and open the most current .log file at Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\LOGS\.  It provides right-click filtering.