Dear Pankaj Singh Rawat, Its mostly because of wrong file or corrupted data file. Does Athena plotted your data? If not, then there is an issue with your data file.
From your screenshot, it looks like you have uploaded XAS data measured at potassium L3 edge.
And looking for Oxygen edge data.
K edge of oxygen is at 0.537 keV but your E0 is at 292.11 (unknown units)
Please check again the data file in a text editor like notepad or word-pad.
Before coming to athena, try plotting your data via some other plotting software like gnuplot.
Make sure the data file doesn't have any un-necessary characters.
See which columns are marked for energy and mu.
I am sure Athena could read wisely.
good luck
Mahendra
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Dr. Uma Mahendra Kumar
Asst Professor of Physics
School of Advanced Sciences
VIT University-Vellore 632 014
Bharat
VIT – Recognised as Institution of Eminence (IoE) by Government of India
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From: Ifeffit