Spreadsheet Uploads:
If you are attempting to upload a spreadsheet containing member data and encountering an error when trying to select a spreadsheet from your computer, the issue may be related to one or all of the headers having spacing problems.
Error:
To resolve this issue, kindly ensure that you verify whether there are spaces after the words in the header. Spaces can lead to complications during the member upload process. Once the spaces have been eliminated, you should be able to upload the spreadsheet successfully.
Figure 1. has no spaces 
Figure 2. has spaces after each category name try hitting the "backspace" key on your keyboard:
Additionally, please remember to save your spreadsheet as a CSV-UTF-8 (Comma delimited) (*.xcsv) file. This will ensure that your upload is done correctly.
If you continue to have problems, please email support at help@epactnetwork.com