Step 1: Please install the current version of the app (3.8.3 or newer)
Step 2: Head to the Settings menu. This can be done by tapping the cog icon in your notification bar.
Step 3: Find Apps (or Applications, depending on your device) in the menu, then locate the app that you want to clear the cache or data for.
Step 4: Tap on Storage and the buttons for clearing the cache and app data will become available.
Step 5: Clear Data
Or you can uninstall the app and install it again.
If these instructions don't work for you, please update the app to the latest version 3.9.3.