This error in Vivado (v2018.3 (64-bit)) occurs and I don't see where the setting is for the xdc write:
I can't create the ".Xil" file location b/c Winderz doesn't like the file name.
I don't see where the pointer for that directory is located in the tool settings.
Thanks for looking at this.
The .Xil is a temporary directory where the tool writes intermediate files. You don't have to manually create it.
I'd suggest that you clean up the .runs directory or recreate the project from scratch and run again.