Use this.
sudo /opt/splunkforwarder/bin/splunk start --accept-license --answer-yes --no-prompt --seed-passwd PASSWORD
Where you see PASSWORD enter your own or populate with a variable.,I found a fix to this when installing Splunk UFC 8.0.1
sudo /opt/splunkforwarder/bin/splunk start --accept-license --answer-yes --no-prompt --seed-passwd PASSWORD
When sub PASSWORD with you password, it'll create the admin account and breeze through the install.
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