Hello Manigandan Arumugam,
Please provide some more details to allow assistance.
- What version of Tableau Desktop and Server?
- Does the visualization utilize a live data source, a published data source or is it an extract? What is the data source?
- Are you seeing the issue only on the dashboard or does the issue exist when looking at the views that comprise the dashboard?
when i click on the dashboard i can see all the thumbnails clearly. but when i click on each view i see few views are blank and few has data.
Hope i answered all your question.
try to refresh the data from the server. You are also working with a version that is a couple of years old. Is this 8.3.0 or has it been updated to the latest rev of 8.3.15 for that version? - You can find the most recent versions of Tableau here: Alternate Downloads Site | Tableau Software
If your account/service is current, I suggest updating to a v10 or at least a v9.x.