Error while upgrading any app like ES content Update app on splunk apps. Its a Mako failed to render error for all apps

[gchauhan]

Hello All

I facing the below error while updating my apps like ES content update Splunk machine learning toolkit or any other app like ES content update. I have gone through the various articles but I am unable to find an answer suitable to updating the apps, can someone please suggest a solution.

2021-06-14 10:53:11,290 ERROR [66c6c494237f7714a7eb50] init.. :361 - Mako failed to render:
Traceback (most recent call last):
File "/opt/splunk/lib/python3.7/site-packages/splunk/appserver/mrsparkle/controllers/__init__.py", line 357, in render_template
return templateInstance.render(**template_args)
File "/opt/splunk/lib/python3.7/site-packages/mako/template.py", line 476, in render
return runtime. _render(self, self.callable_, args, data)
File "/opt/splunk/lib/python3.7/site-packages/mako/runtime.py", line 883, in _render
**_kwargs_for_callable(callable_, data)
File "/opt/splunk/lib/python3.7/site-packages/mako/runtime.py", line 920, in _render_context
exec_template(inherit, lclcontext, args=args, kwargs=kwargs)
File "/opt/splunk/lib/python3.7/site-packages/mako/runtime.py", line 947, in _exec_template
callable_(context, *args, **kwargs)
File "/opt/splunk/share/splunk/search_mrsparkle/templates/layout/base.html", line 15, in render_body
<%self:render/>
File "/opt/ splunk/share/splunk/search_mrsparkle/templates/layout/base.html", line 21, in render_render
<%self:pagedoc/>
File "/opt/splunk/share/splunk/search_mrsparkle/templates/layout/base.html", line 95, in render_pagedoc
<%next: body/>
File "/opt/splunk/share/ splunk/search_mrsparkle/templates/layout/view.html", line 25, in render_body
${next.body}
File "/opt/ splunk/share/splunk/search_mrsparkle/templates/layout/admin.html", line 26, in render_body
${next.body()}
File "/opt/splunk/share/ splunk/ search_mrsparkle/templates/admin/appinstall/upgrade-available.html", line 14, in render_body
escapedAppName = su.escape(appname)
File "/opt/splunk/lib/python2.7/xml/sax/saxutils.py", line 27, in escape
data = data.replace("&", "&amp;")
AttributeError: 'None Type' object has no attribute 'replace'

Any help will be appreciated

Regards

Gaurav Chauhan

@MuS @somesoni2 @aljohnson_splun @sideview @hexx