NCM login does not work

Products

• VMware Smart Assurance
• Network Observability

Issue/Introduction

NCM login screen does not pop up, error observed is

01 Dec 2025 16:09:27,183-[AWT-EventQueue-1] ERROR com.powerup.configmgr.client.app.util.ExceptionHandler [] - java.lang.IllegalArgumentException: Illegal pattern character 'R'
    at java.base/java.text.SimpleDateFormat.compile(SimpleDateFormat.java:849)
    at java.base/java.text.SimpleDateFormat.initialize(SimpleDateFormat.java:657)
    at java.base/java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:628)
    at java.base/java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:603)

Environment

All supported NCM versions 

Cause

NCM User cache was modified in local machine from where NCM is launched. 

Resolution

1. Go to <BASEDIR (C)>\Users\<UserName>\ncm0\var\cache in local machine, rename message.log file
2. Clear Java cache as following
   1. Login to CMD 
   2. Run javaws -clearcache for java or javaws -Xclearcache for OpenWebstart.
3. Launch Thick or Thin client, login prompt will now appear for login. 
4. Provide Username and Password