To @AntiCompositeNumber. As someone who regularly encounters this type of problem, your advice on bigChunkedUpload is very fine. It works. But it baffles me that you are not able to simulate a slow internet connection, so you can actually experience the problems yourself. What does it mean "I time out before the upload does". There should be a setting in the software to give you more time, so you can finally see for yourself what other users are up against. Cheers.

Do not think so.
In T250103 the upload eventually (after pressing "try again" ?) went through, and the problem was seen as solved.
Here there is some sort of time-out that results in a faulty error message.

Hi. This is the error message - from a similar download today:

[[User:Krinkle]] Please read the comments. You need to do this on a s l o w internet connection. And you need to get the message that the servers were busy (time-out). Then you press the "try again"-button and then you will experience an erroneous message faulting your file (png in this case). This has happened to me with around 10 different png files of >10 MB and it is a surefire way to put off inexperienced users.

This problem is not just GIMP-related. I regularly make PNG files with the FastStone Image Viewer - typically from converted jp2-files - and it irritates me considerably that they get such a pale appearance in the thumbs. What can be done?