There are several reasons for the invalid argument. 1 The mobile phone has been poisoned, so it can't operate normally. Please install a housekeeper to kill virus or restore the factory settings. 2. Some system software of WeChat is damaged. Need to uninstall and reinstall. This friend was identified as an illegal account by the system and could not operate normally. 4. If Friend Request is added to the WeChat system for more than 7 days without being processed, the system will automatically stop accepting requests, resulting in invalid parameters.