Do those files actually exist in the listed folders? I spot checked a couple, and they exist here, and are not empty.
Try verifying local files, for both the game and editor.
Are you shutting down all non-essential programs before starting the game, especially anti-virus / security programs?
In one case recently Windows Defender caused 'file not found' errors with dll files in the game's install folder, for example.
Try exiting out of the Steam client, and starting the editor directly from the '..\SteamApps\common\The Divinity Engine 2\DefEd\DivinityEngine2.exe', by right clicking and running as administrator.
Try doing a clean boot and then test the editor. Click Start, or hit WinKey-R, type in msconfig and hit enter; in the General tab, click Selective Startup, uncheck Load startup items (if required) and leave Load system services and Use original boot configuration options checked. Next, click on the Services tab, check the box to Hide all Microsoft services, then click the Disable All button (maybe make a note of which are currently enabled/disabled), then click OK and reboot the computer.
Run msconfig again to switch back to the normal boot configuration.
You may want to check
on Discord, as well. There are more modders there, as well as people from Larian who can offer modding support.
