HCL Sametime Forum : XML Parsing Error: ---stwebapi ----

Hi,
In my environment I've installed IBM Connections and IBM Sametime.
Correctly configured Sametime Awareness, people can chat.

But, in browser Console having Error with stwebapi:

XML Parsing Error: no root element found Location: https://connections.ibm.com/stwebapi/presence Line Number 1, Column 1:
XML Parsing Error: no root element found Location: https://connections.ibm.com/stwebapi/user/capability Line Number 1, Column 1: capability:1:1
XML Parsing Error: no root element found Location: https://connections.ibm.com/stwebapi/buddylist?isWatchList=true&isWatchLocation=true&noCache=1494244578194 Line Number 1, Column 1: buddylist:1:1
XML Parsing Error: no root element found Location: https://connections.ibm.com/stwebapi/user/privacy?noCache=1494244578197 Line Number 1, Column 1: privacy:1:1
XML Parsing Error: no root element found Location: https://connections.ibm.com/stwebapi/preferences?noCache=1494244578198 Line Number 1, Column 1: preferences:1:1
XML Parsing Error: no root element found Location: https://connections.ibm.com/stwebapi/presence Line Number 1, Column 1: presence:1:1
load done _js:56:7
XML Parsing Error: no root element found Location: https://connections.ibm.com/stwebapi/presence Line Number 1, Column 1:

In IBM HTTP Server httpd.conf i add:
ProxyPass /stwebclient http://sametime.ibm.com:9081/stwebclient
ProxyPass /stwebapi http://sametime.ibm.com:9081/stwebapi
ProxyPass /stwebav http://sametime.ibm.com:9081/stwebav
ProxyPass /stbaseapi http://sametime.ibm.com:9081/stbaseapi
ProxyPassReverse /stwebclient http://sametime.ibm.com:9081/stwebclient
ProxyPassReverse /stwebapi http://sametime.ibm.com:9081/stwebapi
ProxyPassReverse /stbaseapi http://sametime.ibm.com:9081/stbaseapi
ProxyPassReverse /stwebav http://sametime.ibm.com:9081/stwebav
ProxyPassReverseCookieDomain http://sametime.ibm.com:9081 ibm.com
ProxyPassReverseCookiePath / /
# end Sametime

How resolve XML Parsing Error?