Layers not showing in ArcGIS Online

[AbbieP]

Hi,

I have some layers which I've uploaded and put into a webmap but they arent showing. They appear in the automatic thumbnail but when I open the feature layer, or place it in a webmap it just has this black line at the top of the layer which moves at it loads. I've left it to load for about an hour but it just keeps loading over and over.

I dont get any errors appear, but the map stays blank and I can't view the data.

Any suggestions on how to fix this will be much appreciated!

[RussRoberts]

Can you share the layers and web map? Are the layers hosted in ArcGIS Online? 

thanks!