Maintenance for the week of January 19:
• PC/Mac: No maintenance – January 19
• NA megaservers for patch maintenance – January 21, 4:00AM EST (9:00 UTC) - 10:00AM EST (15:00 UTC)
• EU megaservers for patch maintenance – January 21, 9:00 UTC (4:00AM EST) - 15:00 UTC (10:00AM EST)
what precisely is your launcher getting stuck on?
the thread i linked shows how to find the report log and determine where the failure occurs. while the cause of your particular issue may differ slightly from the ISP issue (supposedly, according to ZOS anyway), the diagnostic procedure should be the same.