客户端退出登陆后， 再次登陆 就会报 “从服务器上获取资料库同步信息失败：服务器内部错误”

客户端问题
1

客户端第一次登陆 同步资料库都是正常的，
但是退出登陆后， 再次登陆 就会报 “从服务器上获取资料库同步信息失败：服务器内部错误”
这个时候做 解除同步 然后 做同步该资料库 又是正常的，
何解？？

服务器日志：

ROR] django.request:256 handle_uncaught_exception Internal Server Error: /api2/repo-tokens/
Traceback (most recent call last):
  File "/home/seafile/seafile-server-5.1.1/seahub/thirdpart/Django-1.8.10-py2.7.egg/django/core/handlers/base.py", line 132, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/seafile/seafile-server-5.1.1/seahub/thirdpart/Django-1.8.10-py2.7.egg/django/views/decorators/csrf.py", line 58, in wrapped_view
    return view_func(*args, **kwargs)
  File "/home/seafile/seafile-server-5.1.1/seahub/thirdpart/Django-1.8.10-py2.7.egg/django/views/generic/base.py", line 71, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/seafile/seafile-server-5.1.1/seahub/thirdpart/djangorestframework-3.3.2-py2.7.egg/rest_framework/views.py", line 466, in dispatch
    response = self.handle_exception(exc)
  File "/home/seafile/seafile-server-5.1.1/seahub/thirdpart/djangorestframework-3.3.2-py2.7.egg/rest_framework/views.py", line 463, in dispatch
    response = handler(request, *args, **kwargs)
  File "/home/seafile/seafile-server-5.1.1/seahub/seahub/api2/utils.py", line 465, in wrapped
    result = func(*a, **kw)
  File "/home/seafile/seafile-server-5.1.1/seahub/seahub/api2/views.py", line 4111, in get
    if not check_folder_permission(request, repo.id, '/'):
AttributeError: 'unicode' object has no attribute 'id'
2

这个是5.1.1服务器里的bug，下版本里会修复。