Issue

When trying to save a PDF the following error is displayed:

'Could not load file or assembly, Version=9.1.3.139476'

Symptoms

After investigating it was found the Fix Pack was applied before the Cumulative update, which is not the correct procedure. 

Always apply the Cumalative Update before applying the latest following Fix Pack.

This error can also occur if a Repair is run; and the Cumulative Update and Fix pack is not applied again.

Resolution

To resolve this error you have to reapply the Cumulative Update first, then apply the Fix Pack.

 Please note the following article if there is an issue with the rendering of the PDF: https://help.k2.com/kb001626.aspx