Hi there
You can't use your K-50's EyeFi option with a Toshiba FlashAir card.
The availability of the card's WiFi is switched through the lock on the \DCIM\100__TSB\FA000001.JPG image on the card :
Great explanation can be found on
Olympus dedicated Q&A page.
Which version is your card ? Mine is W-03.
Did you format it ? If you did, whether it's from PC or camera, you may have to use the configuration software to restore required files.
For further downloads, you can check
this official page.
Hope this helps.
Best regards.
Alexis.