Circ_Mean Confidence Interval Issues (Circ_Stats toolbox) - Also posted on File Exchange

Hi All, I have posted this question on the file exchange for Circ Stats as well.

My question - I'm trying to calculate the circular mean and 95% CI of a vector of phase values that go from -pi to pi.

Circ_mean calculates mu fine, but my upper/lower limits return NaNs with the message

Warning: Requirements for confidence levels not met. 
> In circ_confmean (line 70) 
In circ_mean (line 53) 
In Phase_Lock_Recall (line 150)

Would you be able to help with this? Do values need to begin at 0 (so add 2pi to my values)?

Thank you! PAK