Importer support for migrated passwords

Thanks. Now the import_users passed, but now it failed on import_categories when executing

raw = process_discuzx_post(row['rules'], nil)
          if @bbcode_to_md
            raw = raw.bbcode_to_md(false) rescue raw
          end
          category.topic.posts.first.update_attribute(:raw, raw)

with error

creating categories
       14 / 52 ( 26.9%)  script/import_scripts/discuz_x.rb:288:in `block (2 levels) in import_categories': undefined method `update_attribute' for nil:NilClass (NoMethodError)
	from /home/localadmin/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/activesupport-5.1.4/lib/active_support/core_ext/object/try.rb:17:in `public_send'
	from /home/localadmin/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/activesupport-5.1.4/lib/active_support/core_ext/object/try.rb:17:in `try!'
	from /home/localadmin/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/activesupport-5.1.4/lib/active_support/core_ext/object/try.rb:6:in `try'
	from /home/localadmin/git/discourse/script/import_scripts/base.rb:451:in `create_category'
	from /home/localadmin/git/discourse/script/import_scripts/base.rb:417:in `block in create_categories'
	from /home/localadmin/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/rack-mini-profiler-0.10.7/lib/patches/db/mysql2.rb:6:in `each'
	from /home/localadmin/.rbenv/versions/2.4.2/lib/ruby/gems/2.4.0/gems/rack-mini-profiler-0.10.7/lib/patches/db/mysql2.rb:6:in `each'
	from /home/localadmin/git/discourse/script/import_scripts/base.rb:398:in `create_categories'
	from script/import_scripts/discuz_x.rb:263:in `import_categories'
	from script/import_scripts/discuz_x.rb:57:in `execute'
	from /home/localadmin/git/discourse/script/import_scripts/base.rb:46:in `perform'
	from script/import_scripts/discuz_x.rb:1065:in `<main>'

Does the last call legal?