I thought the following might be relevant for many of you, especially if you are currently in the 180 day waiting period to be able to retake the Pro test (if this is your case, you may skip the next two paragraphs;-) )
For everyone else, just to have you on the same page: Whenever Pro level testing is open for a language pair and you are qualified (by holdling a Standard qualification or having passed the Pre-Test with 5/5), you have 3 opportunities to take it, with a waiting period of 3 days in-between the trials. Since the evaluation of the test is very strict (and sometimes debatable), only a limited percentage of candidates pass it, it is not unlikely that you fail 3 times in a row.
What's next? The answer seems clear at first. According to the FAQ, "If you fail the test three times, you'll need to wait six months to get another three chances.". And actually, on the Tests tab, you will find a message telling you that you can try it again in x days, where x is a number that counts down from 180 to 0. So whenever you want, you can check how many days are left and look forward to another three challenges.
When the counter reaches 0, the message is replaced by the regular "Take the Pro test to have access to Pro jobs in this pair." and a green Start button.
To my surprise, when I click on that button, all I get is a message that says: "Access denied. You don't have permission to access this part of the site.".
Gengo's support told me that this is because there are no more tests available for EN>DE, and I "already did them all". So, the way they put it, it seemed like it was not a matter of merely not admitting new candidates at the moment, but that there aren't even any more sample texts loaded into the system... so there is no way I could do the test since you are supposed to always get a new text to translate.
They also said the "Access denied" message was "probably due to a visual glitch" and that I should look at the beginning of each month because that's when specific language pairs are usually opened for testing (i.e. the same they would tell totally new candidates). I answered them that this is not what I would call a "visual glitch", but a serious flaw in the logic of the process.
The idea that you can potentially upgrade to an almost professional rate may "help" translators to accept the low Standard rate for a while, and the apparently well-structured process with its cool-down periods is a nice touch, but when this counter turns out to be totally meaningless, you just feel taken for a ride. I hope this will be fixed.
In the meantime, fellow Standard translators: Beware of the "visual glitch" and know what you are in for!!