Hi Hector,
If you click onto the agenda widget within the site designer > Styling Options: Customize > Session Card > Card > Card Background and Border, you will need to adjust the background color as it is currently set to black and therefore, you are unable to see the text. As Steven mentioned, once you click into Session Card, you can also click on "Reset Widget Styles" at the bottom and that will reset it to the default colors/style, which will resolve the issue as well. Event Website Styling 101
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Julia Plymack
Client Success Manager
Cvent
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