# Issues I'm getting in cesium's startRenderLoop

**URL:** <https://community.cesium.com/t/issues-im-getting-in-cesiums-startrenderloop/900>\
**Category:** CesiumJS\
**Created:** [December 27, 2013, 10:50pm UTC](https://community.cesium.com/t/issues-im-getting-in-cesiums-startrenderloop/900 "2013-12-27T22:50:54Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Eugene](https://avatars.discourse-cdn.com/v4/letter/e/8797f3/32.png) [@Eugene](https://community.cesium.com/u/Eugene)\
**Post date:** [December 27, 2013, 10:50pm UTC](https://community.cesium.com/t/issues-im-getting-in-cesiums-startrenderloop/900/1 "2013-12-27T22:50:54Z")

</div>

I currently can add 1 or 2 CzmlDataSources to my application, but anything beyond that (or when I press the ‘home’ button) throws the following error in Viewer’s startRenderLoop function.  
DeveloperError {name: “DeveloperError”, message: “q0, q1, s0, and s1 are required.”

I’m also getting the following error thrown in that same function when I try to morph to 2D or 2.5D views.

RangeError: Invalid array length

Going through the stack trace leads me to believe there’s a time parameter not being set @ Spline.prototype.findTimeInterval… but I’m at a loss for what to do at the moment.

Thanks!