This error appears when attempting to copy and paste a compact combinator with internal circuitry

This issue can be fixed by adding
surface.set_chunk_generated_status(data.chunkPos, defines.chunk_generated_status.entities)
to line 367 of compact-combinator.lua.

Reporting so that this fix can make it into the mod portal.

On further testing, that line needs to be added to line 139 instead.

Thank you for the report I will submit a fix soon.

I've created a pull request on github for this fix.