Error: 'Promise' is undefined

RELATED TO:

AUTHOR: Stephania Tapela

DATE POSTED: July 14, 2017

Article information

Article relates to

Telerik Reporting R2 2017+

Last modified

July 14th 2017

PROBLEM
"Error: 'Promise' is undefined" appears in browser when you load a page with the HTML5 Report Viewer on it.


DESCRIPTION
As of  Telerik Reporting R2 2017, the HTML5 Viewer works in browsers supporting promises.

The error indicates that the tested browser does not have support for promises.
Please check HTML5 Viewer: Important Settings and the requirements for promises.


SOLUTION
If you do not have polyfill Javascript for promises on the page with the HTML5 Viewer, test to add manually a script tag with a link on the page with the viewer.

In our documentation we suggest adding the polyfill file of Polyfill.io. The link with the content of the file can be previewed in a browser that does not have support for promises.

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