ahoeben

Exporting the STL stores the geometry, but not the settings. So you can load the geometry back in but you may not have the same settings as before. Saving a project (which creates a 3MF file) stores the geometry and all settings. You can load it back in, and it will be as if you never closed Cura or made any setting changes. Saving or exporting the gcode will get you a file that no longer contains geometry data, so it cannot be resliced.

@Baldnerd, the latest version of Cura should no longer have that drive letter conflict.

Then I am at a loss

Do you have multiple displays? If so, disable all but one and try starting Cura again.

I just checked, and though I can run Cura 4.9.1 just fine without administrator rights, my logs also include that line about being unable to create a folder in the program files tree. In other words: this particular warning is probably not the reason Cura will not start on your system without Administrator rights.

Start with an M8 or bigger nut and bolt and see how it prints. See what the problem is when printing it upright, and see that you will get other problems in the other directions too. Learn from these experiments. If you want to print the bolt sideways, experiment with sinking it into the buildplate a bit. A bolt does not have to be 100% circular to work. But I would say an m3 thread is too fine to experiment with and learn from.

Just make sure you read the dialogs of the installer of the newer version! You don't have to let the installer uninstall the previous version.

The most obvious advice is: don't print M3 bolts. You can buy them for very cheap (cheaper than you can print them for if you factor in the cost of the printer, maintenance and your time), and the ones you buy will be much stronger. No, you cannot remove the shadow.

Because there are no profiles for it. Making a set of profiles for an Ultimaker printer is a lot of work, requiring a lot of test prints for all combinations of printers, nozzles/printcores, "intents" and qualities. Until very recently there was no Ultimaker-branded PETG, so no single "PETG" to test with (and no incentive to spend money on the profiles, because it would not result in sales of Ultimaker-branded materials, I guess). The UM S5 and S3 support PETG now, and I think I saw on github that the UM 3 will receive profiles for it too in the next version of Cura. I am not sure

The first post in this thread outlines the way to fix this issue. Once you have fixed it, a way to prevent the issue from happening is not logging in to an Ultimaker account, or making sure Cura can access the internet.

Generally speaking, Cura should not be ran as administrator. Doing so may result in other issues (like not being able to run Cura normally, ie not as administrator). Cura should not even try to write to that folder. Programs should not be able to write to folders in Program Files.

I vaguely remembered Lulzbot Cura has a setting to apply "fuzzy" movements in the Z direction, but I might be wrong. That is why I said Ultimaker Cura does has no setting to jitter the z axis, and asked if the user had been using Lulzbot Cura before. Incidentally Lulzbot Cura is stuck at version 3.6.something, so "going back to 3.6" may have some merit after all. But I know less about Lulzbit Cura than I know about Ultimaker Cura. Slightly rotating the model is a creative way to get a fuzzy pattern on top of some models, but you will have to experiment a bit to get a result that lo

The "Compact Prepare Sidebar" plugin is the spiritual predecessor of the "Sidebar GUI" plugin, and only compatible with Cura 3.5/3.6:

The counter crossed 2 million cumulative downloads for all my plugins. Looking at the post date above, that means a million downloads in just under 11 months. That's sort of amazing.

You may be interested in this thread: To make your life easier, see if you can use ```the cryptography module instead of pynacl.