Thomas:
Sorry to hear of your issues with the trial version, which does have limitations. What are you trying to burn: HD or SD?
PD11 always goes to the C:\ drive to create its temporary files, regardless of where the media files or program is located. There have been discussions on this forum that 30 GB free might not be enough free space on the C:\ drive, particularly for HD editing and burning. There have also been issues reported with SSD drives, which is the reason that I went to Velociraptors in RAID0 array when I upgraded to a new computer last year.
Perhaps if you could provide more details of what you are editing, we might be able to help you more. Also attaching a dxdiag file of your computer specs (see sticky thread at top of forum for instructions on how to do that) might help us determine if your computer and drivers are up to the task. From what you have said, your computer, apart from free space on C:\ does not appear, at this point, to be an issue.
Try disabling Hardware Acceleration, if it is turned on, under Preferences. Make sure you have the latest video driver from your GPU manufacturer's website (not a beta version), and ensure that you have the latest and greatest version of QuickTime installed, as PD11 relies on that app.
Hope this helps and good luck solving your problem. If none of the above helps, I would order the full version which not crippled and check that out to see if the problem disappears. You have a 30-day money back guarantee so if it doesn't work and we here on the forum and CL Tech Support can't get PD11 working to your satisfaction, you can apply for a refund.
Have a great day.
Regards,
-Phil
Windows 10 Pro x64
Dell XPS 8930
Intel CoreT i7 (4.6 GHz)
32 GB DDR4-2666 RAM
1 TB PCIe -x4 SSD
NVIDIA GeForce RTX 2060
PD14 Ultimate x64, 4207
CD4 Ultra and AD6 Ultra
Bleeping Computer Malware Response Instructor