“Sometimes there are element in the report that cause null errors and if this occurs, it ussually slows down the js and then requires a restart.” Jaspersoft Community · 7 years ago Jasper Studio upgrade causing issues - Jaspersoft Community
Known fixes for 6.6.0 have addressed initial UI glitches and data adapter connection errors. Step 1: Where to Download Jaspersoft Studio 6.6.0 Fix download jaspersoft studio 660 fix