download lastest version WowzaStreamingEngine-4.7.7-linux-x64-installer.run
#sudo chmod +x WowzaStreamingEngine-4.7.4-linux-x64-installer.run
#sudo ./WowzaStreamingEngine-4.7.4-linux-x64-installer.run
press Enter again
and insert trial key but
Wowza Streaming Engine Setup - Warning: This license key is not valid for version 4. Please enter a valid key.
help!