Sorry, I should have checked
/opt/webwork/webwork2/lib/WeBWorK/Utils/LibraryStats.pm line 71
As instructed in there, I ran update-OPL-statistics.pl and load-OPL-global-statistics.pl. It has corrected the error.
WeBWorK Main Forum
Missing OPL local statistics table
This forum has a limit to the number of forum postings you can make in a given time period - this is currently set at 10 posting(s) in 1 day