How do I slice an *.stl file in Orca slicer? I am only being given the option to load *.3mf files to slice.
I just open them. Right click open with or just drag and drop or open command. Can you do a screen shot? I use the most current and I have 1.8 something as well. Neither gives any issue with STL.
No version of orcaslicer has ever banned the use of STL files.
Just click the Create New Project button and then once you get to the slicer drag the file into the slicer or open it from the menu options.
If a .3mf file can store print settings along with the model, can that be a problem? For example, if I open a .3mf project file in Orca Slicer that was created for a different printer model, will it mess up my local settings?
yes for sure. 3mf for me and using an AMS often will change filament settings and even nozzle sizes and potentially overwrite presets or at least add them.