How to fix 'illegal parameter' in Binance š”
1. Clear cache on your Binance app. Long press the app and go the storage option, then clear cache. You can also go to settings and search storage, then look for the Binance storage cache and clear it.
2. Uninstall and install the Binance app. Then login and you will not be able to find the illegal parameter alert when selling USDT. If the alert is still there, make sure your USDT is not in the earn wallet before selling.
3. Swap currency from funding to spot wallet, before selling any currency.i.e USDT. This will solve the 'illegal parameter' alert.