Hi,
Sorry for the late reply.
I checked your file and I noticed a few things. First, the format was not correct as it didn't have a header for the 1st column. Also, the numbers contained commas, so they were not numbers but strings. Also, the file was not UTF-8 encoded, which is the default in AntConc.
If you want it to work properly, you need to format it as I have in the attached file.
By the way, I'm not sure what you're trying to do with this list, but if you're trying to create a lemmatized word list of your target corpus, this is not the way to do it. The better way is to simply load in your lemma tagged corpus directly into AntConc (using the simple_word_pos_headword_indexer option) and then choose to display lemmas in the word list tool.
I hope that helps.
Laurence.