First, WELCOME!
I know what that error is.. but I can't duplicate it.
So I'm selected on the NL server... I go to the upload test and select a size manually... it works. I run an automatic test and select the sizes manually.. it works. I run other test types.. they work... I run download tests... they work too.
I believe that you got the error... I'm just wondering why. That happens when form data required to process the results is missing from the request.
First, try again... this may have been tied somehow to a glitch earlier that I resolved. (although I doubt it) ... if it persists, please clear your cache and cookies... if it still persists please let me know and I'll look deeper into the issue. You can also directly request tests using the following format.
https://testmy.net/dl-1MB - 1MB Download Test
https://testmy.net/ul-1MB - 1MB Upload Test
Using this format you can manually select 1-200MB download speed tests and 1-33MB upload speed tests. The data is built automatically and sizes are completely dynamic, exactly the size you request, so feel free to use decimals in the sizes. If you were requesting this from a mirror, simply append the subdomain. e.g. 1MB upload test to NL would be http://eu.testmy.net/ul-1MB. Also, enter the size in kB by dropping the 'MB' in the URL. e.g. https://testmy.net/dl-1024 would run a 1024 kB download speed test. -- Pretty nifty little trick, huh!
Thanks for the feedback!
- Damon