If you are using SMB authenticated external storage on your Nextcloud remove it before starting this guide. The migration process will fail if it is not removed.
…I think the instruction here was to remove any configured SMB-based External Storage (i.e. delete it from your configuration) before proceeding with the rest of the guide.
thank you for the db field names, in the meantime I had to manually bring back my data, but maybe some one else running into this problem could use this information and verify if its working