It's 99 percent certain that it is to do with my computer and how it is set up, but I've not consciously changed anything recently.
For the last week or so if I try and download calibration files, I can only do so one at a time from the list. Whereas before I could select one after the other, as soon as I select a second one nothing happens.
The solution, which is a bit of an inconvenience, is to close the tab in the browser, reselect a new tab, start roboscopes again, select calibration files, then the pier you want and then the next set you want, eg 60 second darks. For pier 8 this is proving even more so, since the bias is set up as 20 individual files and not as a bias set. Took about 15 minutes to just get the bias.
I'm sure no-one else has been experiencing this but if you have, have you found a quicker solution?