Illustrator 2020 v24.1.1 - "Real-Time Drawing and Editing" can't save new symbol
I tested the new Real-Time Drawing and Editing feature today and found that once I finished my drawing, dragging it over to the Symbols pane to create a new symbol as I normally would resulted in the attached error.
This was the first bit of work I had done since enabling this new feature so I suspected it was the cause and I moved on to two other projects to confirm. One of those worked correctly - the simpler project - and the other did not. So two out of three drawings could not be turned into symbols, and the error message gives no indication of what exactly it doesn't like about my output.
I still hit this error after saving my files, restarting Illustrator and trying again. Disabling "Real-Time Drawing and Editing" fixes this right away and I'm able to use Illustrator as I always have.
All of these projects are relatively complex technical drawings but nothing unreasonable, and certainly simpler than what a lot of folks in the community crank out.
Please let me know if there's any more info that would help.
Illustrator version 24.1.1
Windows 10 Enterprise, build 17134
Lenovo Thinkstation P520c
Intel Xeon W-2133 CPU
NVIDIA Quadro P4000, 8GB. Driver version 440.97
Thanks for reporting this issue.
We are able to reproduce this issue and investigating this further.
I've emailed you with a sample file and some more information. The presence of brush strokes seems to be a factor.