Hello~ I have used Larch 0.9.71. until now. However, I would like to update larch and I reinstall anaconda and larch. I installed Larch 0.9.74. as following installation guide I didn't have any problems during the installation process. However, I faced problems during feffit fitting. Before, I used feffit fitting in larch 0.9.71., and then I hadn't had any problems. I changed larch as new version. What am I doing? When I run feffit fitting in python, I have debugs as the below: ------------------------------------------------------------------------------------------------------------------------- File "c:\Users\Administrator\Desktop\RL\feffit_error_test\test-feffit.py", line 51, in <module> out = feffit(pars, dset) ^^^^^^^^^^^^^^^^^^ File "C:\ProgramData\anaconda3\envs\xraylarch\Lib\site-packages\larch\xafs\feffit.py", line 645, in feffit ds.prepare_fit(params=params, other_hashkeys=dset_hashkeys) File "C:\ProgramData\anaconda3\envs\xraylarch\Lib\site-packages\larch\xafs\feffit.py", line 374, in prepare_fit self._generate_hashkey(other_hashkeys=other_hashkeys) File "C:\ProgramData\anaconda3\envs\xraylarch\Lib\site-packages\larch\xafs\feffit.py", line 291, in _generate_hashkey dat = [self.data.ek0, self.data.e0, self.data.rbkg] ^^^^^^^^^^^^^ AttributeError: 'Group' object has no attribute 'ek0' ---------------------------------------------------------------------------------------------------------------------- The data(EXAFS(k)), which are inputted for feffit, have two column, k and chi. As you know, it doesn't have ek0. -- Best regards, Ph. D. Eun-Suk Jeong X-ray absorption fine structure(EXAFS+XANES) Mobile:+82-10-4628-9896