eWallet for Mac no longer supports OS X 10.6 (Snow Leopard), or older. 

eWallet for Mac 8.5 (and newer) is compatible with macOS 10.13 or later (High Sierra, Mojave, Catalina, and Big Sur).

eWallet for Mac 8.3.9 — 8.4.3 is compatible with macOS 10.12 or later (includes Sierra, High Sierra, Mojave, Catalina, and Big Sur).

eWallet for Mac 8.0 — 8.3.8 is compatible with macOS (formerly Mac OS X) 10.9 — 10.13, (includes Mavericks, Yosemite, El Capitan, Sierra and High Sierra).  

You should be able to update to the latest version of eWallet via the Mac App Store.

If you still have problems starting eWallet after updating, you may have to clear eWallet's old preference information. You can do that through the terminal.

1. Make sure eWallet is not running (if an old version of eWallet won't quit normally, go to the Force Quit menu selection in the Apple menu, then select eWallet in the list and press the Force Quit button)
   
   

2. Open the Terminal app (Applications -> Utilities -> Terminal)

3. Copy and paste this line into the terminal and press enter:  cd ~/Library/Saved\ Application\ State/

4. Copy and paste this line into the terminal and press enter: rm -rf com.iliumsoft.eWallet.mac.savedState