Fir the error message suggest that you have been using the command CREATE EXTERNAL LIBRARY in the database. I wold expect the statement SELECT *FROM sys.external_libraries
to return at least one row.
But this external library may not be in best shape, since the error code 0x80070003 is the error The system cannot find the path specified. Then again, if the folder is gone, the error is sort of benign. (Although, if you actually try to use the external languages, you are likely to get problems.)