Error after git pull

Getting the following error after git pull. The error has been logged in the web.error.log file. The browser shows “Internal Server Error”. Supervisorctl is running properly, all processes are in RUNNING mode.

[5730] [ERROR] Error handling request /favicon.ico
Traceback (most recent call last):
  File "/opt/erpnext/erpnext/apps/frappe/frappe/app.py", line 54, in application
    init_request(request)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/app.py", line 133, in init_request
    raise frappe.SessionStopped('Session Stopped')
frappe.exceptions.SessionStopped: Session Stopped

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 50, in render
    data = render_page_by_language(path)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 177, in render_page_by_language
    return render_page(path)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 193, in render_page
    return build(path)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 200, in build
    return build_page(path)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 223, in build_page
    html = frappe.get_template(context.template).render(context)
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/environment.py", line 1090, in render
    self.environment.handle_exception()
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/environment.py", line 832, in handle_exception
    reraise(*rewrite_traceback_stack(source=source))
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/_compat.py", line 28, in reraise
    raise value.with_traceback(tb)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./www/message.html", line 1, in top-level template code
    {% extends "templates/web.html" %}
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./templates/web.html", line 1, in top-level template code
    {% extends base_template_path %}
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./templates/base.html", line 57, in top-level template code
    window.dev_server = {{ dev_server }};
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./templates/base.html", line 58, in block "navbar"
    window.socketio_port = {{ (frappe.socketio_port or 'null') }};
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/sandbox.py", line 462, in call
    return __context.call(__obj, *args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/utils/jinja.py", line 199, in web_block
    return web_blocks([options])
  File "/opt/erpnext/erpnext/apps/frappe/frappe/utils/jinja.py", line 224, in web_blocks
    out = get_web_blocks_html(web_blocks)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/doctype/web_page/web_page.py", line 221, in get_web_blocks_html
    web_template = frappe.get_cached_doc('Web Template', block.web_template)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 747, in get_cached_doc
    doc = get_doc(*args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 790, in get_doc
    doc = frappe.model.document.get_doc(*args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/model/document.py", line 75, in get_doc
    return controller(*args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/model/document.py", line 113, in __init__
    self.load_from_db()
  File "/opt/erpnext/erpnext/apps/frappe/frappe/model/document.py", line 156, in load_from_db
    frappe.throw(_("{0} {1} not found").format(_(self.doctype), self.name), frappe.DoesNotExistError)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 409, in throw
    msgprint(msg, raise_exception=exc, title=title, indicator='red', is_minimizable=is_minimizable, wide=wide, as_list=as_list)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 388, in msgprint
    _raise_exception()
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 342, in _raise_exception
    raise raise_exception(msg)
frappe.exceptions.DoesNotExistError: Web Template Standard Navbar not found

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/gunicorn/workers/sync.py", line 135, in handle
    self.handle_request(listener, req, client, addr)
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/gunicorn/workers/sync.py", line 176, in handle_request
    respiter = self.wsgi(environ, resp.start_response)
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/werkzeug/local.py", line 231, in application
    return ClosingIterator(app(environ, start_response), self.cleanup)
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/werkzeug/wrappers/base_request.py", line 237, in application
    resp = f(*args[:-2] + (request,))
  File "/opt/erpnext/erpnext/apps/frappe/frappe/app.py", line 82, in application
    response = frappe.utils.response.handle_session_stopped()
  File "/opt/erpnext/erpnext/apps/frappe/frappe/utils/response.py", line 223, in handle_session_stopped
    return frappe.website.render.render("message", http_status_code=503)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 63, in render
    data = render_page('404')
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 193, in render_page
    return build(path)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 200, in build
    return build_page(path)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/render.py", line 223, in build_page
    html = frappe.get_template(context.template).render(context)
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/environment.py", line 1090, in render
    self.environment.handle_exception()
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/environment.py", line 832, in handle_exception
    reraise(*rewrite_traceback_stack(source=source))
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/_compat.py", line 28, in reraise
    raise value.with_traceback(tb)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./www/404.html", line 1, in top-level template code
    {% extends "templates/web.html" %}
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./templates/web.html", line 1, in top-level template code
    {% extends base_template_path %}
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./templates/base.html", line 57, in top-level template code
    window.dev_server = {{ dev_server }};
  File "/opt/erpnext/erpnext/apps/frappe/frappe/./templates/base.html", line 58, in block "navbar"
    window.socketio_port = {{ (frappe.socketio_port or 'null') }};
  File "/opt/erpnext/erpnext/env/lib/python3.6/site-packages/jinja2/sandbox.py", line 462, in call
    return __context.call(__obj, *args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/utils/jinja.py", line 199, in web_block
    return web_blocks([options])
  File "/opt/erpnext/erpnext/apps/frappe/frappe/utils/jinja.py", line 224, in web_blocks
    out = get_web_blocks_html(web_blocks)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/website/doctype/web_page/web_page.py", line 221, in get_web_blocks_html
    web_template = frappe.get_cached_doc('Web Template', block.web_template)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 747, in get_cached_doc
    doc = get_doc(*args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 790, in get_doc
    doc = frappe.model.document.get_doc(*args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/model/document.py", line 75, in get_doc
    return controller(*args, **kwargs)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/model/document.py", line 113, in __init__
    self.load_from_db()
  File "/opt/erpnext/erpnext/apps/frappe/frappe/model/document.py", line 156, in load_from_db
    frappe.throw(_("{0} {1} not found").format(_(self.doctype), self.name), frappe.DoesNotExistError)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 409, in throw
    msgprint(msg, raise_exception=exc, title=title, indicator='red', is_minimizable=is_minimizable, wide=wide, as_list=as_list)
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 388, in msgprint
    _raise_exception()
  File "/opt/erpnext/erpnext/apps/frappe/frappe/__init__.py", line 342, in _raise_exception
    raise raise_exception(msg)
frappe.exceptions.DoesNotExistError: Web Template Standard Navbar not found 

Any help please.

try running bench migrate