I wanted to process my data in GenALEx but am facing with warning message "GenAlEx is unable to proceed! The current active worksheet 'xxx' does not appear to contain valid raw data starting in Cell C4. Are you sure this worksheet contains your data?"

I work on Mac with Excel 2011, GenAlEx has been installed without any problem. I have successfully imported sequence data, I am in the right worksheet, sequences start in the cell C4 - everything looks correct but I cannot do anything. Whatever I try, the warning message appears. I tried newer, older versions of GenAlEx, own data as well as example data, nexus and fasta files, saved the data workbook as .xls and .xlsx but nothing helped.

I would greatly appreciate any suggestion where the problem might be.

Thanks