The CurvyCorners script is applying its rounded corners on the fly and DOM elements added or initialized later are not taken into account, thus they will probably break/look strange (additionally hover state rounded corners do not work at all). Another issue is that CurvyCorners is heavily modifying the HTML of the elements it initializes and inserts literally hundreds of DIV elements in every rounded corner element it detects. This brings other issues with the Kendo UI widgets which don't expect these elements and try to initialize wrong ones. Due to its behavior, we can say that it is incompatible with Kendo UI and we don't see how such compatibility can be implemented.
the Telerik team
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