First, when you attempt to go online with the PLC shows the library version as being incorrect, is it showing you the version you have or, the version it wants?

Rightmost image is the result of me trying to go online it displays 3.3.10.0. The center image is the library repository for that tc2_serialcom heading. It shows versions 3.3.6.0 to 3.3.7.1. Leftmost image is the file I downloaded from beckhoff to try and update it to 3.3.10.0. 

How do I verify which version is actually correct?

How do I select different installed versions?

Where do I download that correct version from beckhoff?