problem with acquiring root privileges

[Android Question]

Sprint HTC EVO 4G LTE, phone is rooted, TWRP, SuperSU and Titanium backup. Rooted to use WiFi tether. Was working fine for quite awhile had an issue now and then but was able to get it going again. Now started having issues and can't seem to resolve. Titanium can't acquire root privileges. Checked and phone with Root Checker and it is still rooted.
I didn't root the phone and I am not sure what I am doing. I don't understand all the TWRP options/selections and I don't want to completely mess up my phone.

This is the Error message from Titanium Backup:

(Sorry, I could not acquire root privileges. This application will*not*work! Please verify that your ROM is rooted, and try again.
This attempt was made using the

 

[Rukbat]

Some root programs only put one copu of su - in /system/bin, not /system/xbin.

Before you mess the phone up and have to pay to have it repaired, post your location and maybe someone near you can help you set it up properly.

(Someone on XDA forums has, as a sig line, something to the effect that no one who can't root a phone manually should have a rooted phone. Since rooting, and understand what rooting is and how it's done, are so simple, his sig is very true.)

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