what’s the problem you are referring to ? I might be wrong, but so far, I can’t remember a big difference in decryption commands between ownCloud 10.0 and the current one.
Maybe have a look in this ownCloud 10.0 manual
This seems related to Decrypt all files with recovery key so you probably have user-key-based encryption in place and your question is about decrypting all users’ files using the global recover-key password. In this case, please check the suggestion in the linked topic.
About module with id: OC_DEFAULT_MODULE does not exist this is likely because you already tried to unsuccessfully decrypt the files so you may need at this point to re-enable the module by running occ encryption:enable
I have first moved the complete install to another server where i have enough space to make extra backups. The situation before the problem with 2 users that forgot there passwords is restored.
I found in the tables that one of this users was created without marking that the global recover-key should be used.
I hope that updating to newer versions will make the chance on recovering the files to an unencryted version will be better after several updates.
I have now 5 copies of a complete 37 Gb install and had to reserve one whole server to get the install uptodate and solve the problems. I offered this for little money as a service but it grew to an install with over 100 users, they have to be patient and i have to be carefull.