Okay so i've ran into this issue before- and here's how I solved it
Step 1. Uninstall Warband on your computer completely, delete any folders, residue, cheeto dust, anything left behind.
Step 2. Reinstall it
Step 3. Turn off your device
Step 4. Turn on your device
Step 5. Go to Steam and log out of your account
Step 6. Go to the "create a new account" and make a new one
Step 7. Stop being a filthy whore and pay $5 for a new key
Step 8. Have lazy devs transfer items and data over
Step 9. install c-rpg on new warband
Step 10. Play for hours and hours straight until you pass out and die from sleep deprivation and lack of pooping