I am running the latest emacs compiled from source (27.0.50). My configuration parameters are in the configure.txt attached file.
My problem:
M-x eww RET arxiv.org RET
returns the error in the title of this message:
error in process filter: Window system frame should be used
I am attaching the debugger trace produced upon setting debug-on-error to 't' (the file is trace.txt).