When a new theme version is released / updated, the translation .po must be updated as well to find the new terms – http://www.marketpressthemes.com/blog/how-to-merge-two-po-files-using-poedit/

Step #1

Open up your existing language PO file with Poedit software.

Step #2

Go to Catalogand selectUpdate from POT file

Step #3

First, change the file type option to All Files, then select the new wprentals.po PO file from latest theme update folder

Step #4 (OPTIONAL)

Next, you’ll see a mini box which includes all the new strings as well as obsolete string from the new PO file. Proceed by clicking the okbutton.

Step #5

Once the import is completed, all the new string from the new PO file will be added and your existing (translated) string will remain intact as well.

Step #6

Finally, proceed to translate all the new string into your preferred language. Save. Move the updated .po and .mo language file back to wpresidence/languages or to child theme languages folder.