当我尝试重新启动 open erp 7 服务器时，出现以下错误。我无法解决此错误，因为我是开发 open erp 7 的新手。
2013-07-01 11:07:20,331 17513 ERROR db_timeseet openerp: Failed to initialize database `db_timeseet`.
Traceback (most recent call last):
File "/home/fabian/openerp-7.0-20130605-231041/openerp/cli/server.py", line 97, in preload_registry
db, registry = openerp.pooler.get_db_and_pool(dbname,update_module=update_module)
File "/home/fabian/openerp-7.0-20130605-231041/openerp/pooler.py", line 33, in get_db_and_pool
registry = RegistryManager.get(db_name, force_demo, status, update_module)
File "/home/fabian/openerp-7.0-20130605-231041/openerp/modules/registry.py", line 192, in get
update_module)
File "/home/fabian/openerp-7.0-20130605-231041/openerp/modules/registry.py", line 218, in new
openerp.modules.load_modules(registry.db, force_demo, status, update_module)
File "/home/fabian/openerp-7.0-20130605-231041/openerp/modules/loading.py", line 341, in load_modules
processed = load_marked_modules(cr, graph, states_to_load, force, status, report, loaded_modules, update_module)
File "/home/fabian/openerp-7.0-20130605-231041/openerp/modules/loading.py", line 256, in load_marked_modules
loaded, processed = load_module_graph(cr, graph, progressdict, report=report, skip_modules=loaded_modules, perform_checks=perform_checks)
File "/home/fabian/openerp-7.0-20130605-231041/openerp/modules/loading.py", line 165, in load_module_graph
init_module_models(cr, package.name, models)
File "/home/fabian/openerp-7.0-20130605-231041/openerp/modules/module.py", line 374, in init_module_models
result = obj._auto_init(cr, {'module': module_name})
File "/home/fabian/openerp-7.0-20130605-231041/openerp/osv/orm.py", line 3182, in _auto_init
raise except_orm('Programming Error', 'There is no reference available for %s' % (f._obj,))
except_orm: ('Programming Error', 'There is no reference available for min.span.class')