I did a search here on critical errors but didn't see anything with the same message below ...
There was an error while processing a database query
While executing query "SELECT count(*) FROM cpg_pictures as p, cpg_albums as a WHERE p.aid = a.aid AND category >= 10000" on 0
mySQL error: Can't open file: 'cpg_pictures.MYI'. (errno: 138)
http://forum.coppermine-gallery.net/index.php?topic=10409.0
Totally clueless here as you can tell ... I get where you're telling me to go and fix it but where can I find the name to my table?
The name of your table is cpg_pictures (it's in your error message).