Trying to test my domain to verify leaks of Vuln..

and I keep getting:

[INFO] target url appears to be UNION injectable with 7 columns -- (sometimes this changes into different amounts)
[WARNING] please consider usage of --union-char option (e.g. --union-char=1) to make it work

I first ran the same command below without the union-char option and it shot out the same warning line...but then
I re-ran it with the added option to the command and its taking for ever, and its shooting out the same warning message, but no dumping...

/ -u --dump-all -o threads=10 --random-agent --timeout=60 --retries=6 --level=5 risk=3 --beep --batch --union-char=1