Table 'wikidb.knowledge_archive' doesn't exist
Fragment of a discussion from Project:Support desk
Sounds like the archive table, using a db prefix of knowladge_ (or at least that's where that table name would come from). However it appears you're using a db prefix of pcloskb, not knowladge.
This sounds like a webmin issue more than a MediaWiki issue. Perhaps try using a different tool to back up your wiki