Gerbview seems to have a limited understanding of Excellon drill files. I have a drill file from STM which includes both the METRIC header command without argument and the R command for repeat in the main section. Both are reported as errors in Gerbview. Products such as Gerbv work fine. Anyone else got these kind of problems and will it be resolved?
Raise a bug report.
I noticed some commits on GitHub today to do with the METRIC statement