Unable to set a schedule

[BruceAnderson]

I have two datasets, for some reason the refresh schedule has dissapered.  And now when I click on "Schedule Refresh" to set it up again, there are no options shown, the little arrow points down, but nothing shows.  I tried it in IE and FF, also tried clearing cache.  Is this an issue with the site, or my datasets/gateway?

[BruceAnderson]

I have tried now reinstalling the gateway, and installing on another machine, but to no avail.  The site tells me that the credentials are missing, but the option to set the credentials is missing.  (That is mentioned here: https://powerbi.microsoft.com/en-us/documentation/powerbi-admin-troubleshooting-power-bi-personal-ga... I also tried re-uploading my excel file but the result is the same.  Would anyone be able to point me in some direction?