Odoo Server Error

Traceback (most recent call last):
  File "/odoo/odoo-server/openerp/http.py", line 599, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/odoo/odoo-server/openerp/http.py", line 636, in dispatch
    result = self._call_function(**self.params)
  File "/odoo/odoo-server/openerp/http.py", line 315, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/odoo/odoo-server/openerp/service/model.py", line 118, in wrapper
    return f(dbname, *args, **kwargs)
  File "/odoo/odoo-server/openerp/http.py", line 308, in checked_call
    result = self.endpoint(*a, **kw)
  File "/odoo/odoo-server/openerp/http.py", line 887, in __call__
    return self.method(*args, **kw)
  File "/odoo/odoo-server/openerp/http.py", line 465, in response_wrap
    response = f(*args, **kw)
  File "/odoo/odoo-server/addons/web/controllers/main.py", line 971, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/odoo/odoo-server/addons/web/controllers/main.py", line 963, in _call_kw
    return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)
  File "/odoo/odoo-server/openerp/api.py", line 238, in wrapper
    return old_api(self, *args, **kwargs)
  File "/odoo/odoo-server/openerp/models.py", line 1536, in fields_view_get
    root_view = View.read_combined(cr, uid, view_id, fields=['id', 'name', 'field_parent', 'type', 'model', 'arch'], context=context)
  File "/odoo/odoo-server/openerp/api.py", line 238, in wrapper
    return old_api(self, *args, **kwargs)
  File "/odoo/odoo-server/openerp/addons/base/ir/ir_ui_view.py", line 635, in read_combined
    view_arch = etree.fromstring(view['arch'].encode('utf-8'))
  File "lxml.etree.pyx", line 3032, in lxml.etree.fromstring (src/lxml/lxml.etree.c:68106)
  File "parser.pxi", line 1785, in lxml.etree._parseMemoryDocument (src/lxml/lxml.etree.c:102455)
  File "parser.pxi", line 1673, in lxml.etree._parseDoc (src/lxml/lxml.etree.c:101284)
  File "parser.pxi", line 1074, in lxml.etree._BaseParser._parseDoc (src/lxml/lxml.etree.c:96466)
  File "parser.pxi", line 582, in lxml.etree._ParserContext._handleParseResultDoc (src/lxml/lxml.etree.c:91275)
  File "parser.pxi", line 683, in lxml.etree._handleParseResult (src/lxml/lxml.etree.c:92461)
  File "parser.pxi", line 622, in lxml.etree._raiseParseError (src/lxml/lxml.etree.c:91757)
XMLSyntaxError: Opening and ending tag mismatch: span line 65 and sheet, line 66, column 26