Try using a different browser and turning off ad blockers and pop-up blockers.
Under certain circumstances, some people might experience problems downloading their projects. The common denominator for this seems to be the browser. Most people who are experiencing issues are using a browser called Brave, however, we've also heard of some users experiencing issues with other browsers. In most cases, the issue seems to be resolved when they switch or test a different browser to download the files. We also recommend turning off any ad-blockers or pop-up blockers.
If you're having issues downloading from Studio, make sure you are following the correct flow as you don't download audio in Studio the same way you do in Speech Synthesis.
To create a new version of your chapter or project, which will then be downloaded, you need to use the Export button. You have the option to create a new export of either the current chapter, or your entire project. If you've made any changes since your last export, you will see a confirmation of how many credits it will take to create the new export. You'll only be charged credits for paragraphs that have not already been converted, or that have been edited since your last export and therefore need to be converted again.
You can also access all your previous exports. To do this, click the Project options button, then select Exports.