Most importantly, if you paid a once-off charge for a video export and the process failed without your video getting downloaded, e.g. because the page reloaded, showed an error or your computer went to sleep, there won't be a charge on your card and any "pending authorisation" that might get shown will automatically expire after some time.
To try exporting again at a higher resolution, the following steps can help:
- clear the browser cache (only select "cached images and files", "of all time"),
- restart Chrome and make sure not to use incognito mode,
- reload the editing project by hitting the Ctrl & F5 keys at the same time,
- close other browser tabs and applications that might be running in the background to free up some extra memory,
- try a test export at 480p
- during the exporting, keep the Clipchamp page in the foreground otherwise Chrome can take away processing resources from it
If the above doesn't help,
- compress the video files (e.g. at https://util.clipchamp.com/en/dashboard) and use the resulting MP4 videos in the editing project. Smaller files get processed more reliably.
Note that depending on the length, format and file size of the videos you're adding to the project and the computer you're using (age of the computer, operating system, amount of free memory, type of graphics card and CPU), the video processing might take up too many resources as it's quite compute-intense.
This is due to Create running in the browser but it is using the local computer's processing so works a bit like a hybrid between an installed application and an online app.