Yesterday evening MTurk made a change to how the website operates. Now when you accept a HIT the response sets a "cookie" in your browser with information about the HIT (no clue why or the purpose). This is fine if you accept HITs & submit them all from the exact same browser and the same profile/session. However if you accept HITs in one browser/profile, and return/submit from another one, the cookies will not expire properly and can cause all of your requests to MTurk to be overloaded when sending these cookies to the server. Right now (as of June 20th, 2019 2PM EST) these cookies have absolutely no purpose other than to break the website functionality of anyone using advanced workflows/scripts, so the suggested solution to resolving the issue w/o giving up your workflow is as follows: ***IMPORTANT*** You only need to follow these steps for the browser/profile you accept HITs from In Chrome, Opera, Vivaldi and other Chromium based browsers install EditThisCookie from here: https://chrome.google.com/webstore/detail/editthiscookie/fngmhnnpilhplaeedifhccceomclgfbg?hl=en Be careful with Opera & possibly other non-Chrome browsers, the extension tends to not be up to date on their extension stores so use the Chrome version of it In FireFox you can try this but I don't have detailed instructions for it, sorry: https://cookie-editor.cgagnier.ca/ Right click the extension icon and go to Options From the options click on "Blocked cookies" on the left navigation pane, on the right hand side click "block cookie" and enter a record as shown in the screenshot: Domain: worker.mturk.com Name: Hit-* Value: any Use chrome://restart (or just completely close out of your browser & reopen it for other installs) to make sure the changes take full effect This will prevent MTurk from setting these cookies so if they actually implement some functionality around this at a later date this guide may impair your ability to use MTurk. PLEASE send in a support ticket with MTurk and let them know whatever they are trying to do is a bad solution because even at 25 HITs in a queue they are dangerously close to the request maximum when implementing these cookies and if they append any more information to these things MTurk will be grinding to a halt for everyone.