Cannot access web pages

Hello,
We suddenly cannot connect to web interface. Getting the following:
Web page is unavailable - Sorry, but the requested page is unavailable due to a server hiccup.

We tried to clear cache, use different browser, etc…

Seattle client work for all users.

Any idea - what could the problem?

System info:
Windows 2008 R2
Python 2.7.13
Seattle 6.0.7

2017-05-08 10:06:14,424 [ERROR] django.request:256 handle_uncaught_exception Internal Server Error: /accounts/login/
Traceback (most recent call last):
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\core\handlers\base.py”, line 223, in get_response
response = middleware_method(request, response)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\contrib\sessions\middleware.py”, line 50, in process_response
request.session.save()
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\contrib\sessions\backends\db.py”, line 56, in save
return self.create()
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\contrib\sessions\backends\db.py”, line 41, in create
self.save(must_create=True)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\contrib\sessions\backends\db.py”, line 65, in save
obj.save(force_insert=must_create, using=using)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\models\base.py”, line 734, in save
force_update=force_update, update_fields=update_fields)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\models\base.py”, line 762, in save_base
updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\models\base.py”, line 846, in _save_table
result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\models\base.py”, line 885, in _do_insert
using=using, raw=raw)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\models\manager.py”, line 127, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\models\query.py”, line 920, in _insert
return query.get_compiler(using=using).execute_sql(return_id)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\models\sql\compiler.py”, line 974, in execute_sql
cursor.execute(sql, params)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\backends\utils.py”, line 64, in execute
return self.cursor.execute(sql, params)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\utils.py”, line 98, in exit
six.reraise(dj_exc_type, dj_exc_value, traceback)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\backends\utils.py”, line 64, in execute
return self.cursor.execute(sql, params)
File “C:\SeafileProgram\seafile-server-6.0.7\seahub\thirdpart\django-1.8.10-py2.7.egg\django\db\backends\sqlite3\base.py”, line 318, in execute
return Database.Cursor.execute(self, query, params)
DatabaseError: database disk image is malformed
2017-05-08 10:06:15,045 [WARNING] django.request:170 get_response Not Found: /favicon.ico