Under Library, Package it is possible to upload NuGet package. This works fine with Chrome and IE11, but not with IE10 and Firefox 41.0.2 !
With IE 10 you must click twice on the button “Upload” and then the process icon is displaying. But the process icon is displaying for ever. With Firefox also the text in the warning box (yellow background -> see attachment) isn’t readable.
With IE11 and Chrome 46.0.2490 I haven’t any problems.
Thanks for reaching out. I’ve tested the upload on Firefox 41 and 42 and it worked as expected. When trying to upload a package that already existed, it triggered the expected error, but the message couldn’t be seen. I’ve logged an issue for that -> https://github.com/OctopusDeploy/Issues/issues/2122
RE IE10, its a 3 year old browser and even if I submit an issue saying you have to click twice to make the upload work, its very unlikely we’ll do something about it. Updating to IE11 would be the recommended workaround, not only for this particular fix but for all the security improvements that upgrading your browser implicates.