...
Just watch the orange notification icon 
next to your workbook tabs and click on them (1).
Then you can see the problem messages and fix them with 1 click (2).
Page Comparison
Manage space
Manage content
Integrations
...
Just watch the orange notification icon next to your workbook tabs and click on them (1).
Then you can see the problem messages and fix them with 1 click (2).