If WebSphere Integration Developer (WID) V126.96.36.199 is installed simultaneously with V7, or is upgraded directly from V188.8.131.52 or prior V7.0.0.x release, then WebSphere Integration Developer V184.108.40.206 is unable to launch.
The screenshot below illustrates the configuration error observed when launching WebSphere Integration Developer V220.127.116.11 after going through the above described install/upgrade path.
The workaround is to upgrade to WebSphere Integration Developer V18.104.22.168 or V22.214.171.124 Interim Fix 001 first prior to installing or updating to WID V126.96.36.199.
For the upgrade problem, another workaround is in the file "<WID_Install>/Configuration/config.ini", specify the value "-Dorg.eclipse.update.reconcile=true" at the end of the file, then re-launch WebSphere Integration Developer V188.8.131.52.
For more details and the cause, see technote #1598651