Problem

After migrating Confluence from Data Center to Server edition, Collaborative Editing cannot be enabled. 

The following appears on screen after clicking Change Mode > Enabled on the Collaborative Editing menu at: <base-url>/admin/confluence-collaborative-editor-plugin/configure.action

We couldn't connect to your Synchrony cluster from this Confluence node. 

Diagnosis

Environment

• Confluence Server 6.6.x (migrated from Data Center)

Diagnostic Steps

• When attempting to enable Collaborative Editing, the error in the below screenshot is displayed. 
  • 
• In the able screen, note that Synchrony URL is displayed on the bottom right under configuration - this should only appear in Data Center instances. Server instances should look like this:
  • 

• The following configuration settings are in confluence.cfg.xml: 

      <property name="synchrony.btf">false</property>

Resolution

1. Update confluence.cfg.xml and set synchrony.btf to true: 

       <property name="synchrony.btf">true</property>

2. Add the following parameter to setenv.sh (or setenv.bat for Windows): 

   CATALINA_OPTS="-Dsynchrony.proxy.enabled=true {CATALINA_OPTS}"

3. Restart Confluence
4. Enable Collaborative Editing 
   1.  > General Settings > Collaborative Editing
   2. Click Change Mode
   3. Click On
   4. Click Change