WordPress Updates Fails with cURL error 18: transfer closed with X bytes remaining to read

While doing routine WordPress updates I came across this error:

cURL error 18: transfer closed with X bytes remaining to read

After some investigation I found that my hosting server was unable to download files. Much of the advice I found suggests issues with cURL, PHP, or WordPress. If possible I advise checking the host server first. Verify that it can download the update file.

Attempting to get PHP 5.6 running on Windows Server 2012 (IIS 8) I started receiving generic 500 errors.

I enabled Failed Request tracing and reviewed the trace.

The trace revealed this error:

ModuleName FastCgiModule
ErrorCode The extended attributes are inconsistent. (0xff)

The problem was a missing Visual C++ runtime.

Ensure the appropriate VC++ runtime is installed for the version of PHP running.

In this case I needed the VC++ 11 runtime.

about me

An information technology professional with twenty one year's experience in systems administration, computer programming, requirements gathering, customer service, and technical support.