Have you enabled Folders_g and WcConfigure components on UCM side ?
You can check this from UCM - Administration - Configuration Information - Enabled Components Section .
Try useful info at -http://yonaweb.be/configuring_webcenter_content_webcenter_spaces_ps5
Thanks for your reply. I have enabled the neccessary components in UCM (Foders_g, WebcenterConfigure, Dynamic Converter).
When I worked in 220.127.116.11.0 spaces I didn't faced this error but I'm new to 18.104.22.168 spaces.
But the error says The Documents service is not enabled for this Portal or a parent Portal.
Is there any configuration from Spaces side, other than UCM side. Because when I add the the taskflow, I see no error log in UCM.