Hi Martin,
We have analyzed the reported issue and the code snippets that you have shared with us. We suspect that you would have missed out to refer the scripts and css files in your project.
The scripts and the css files can be found in the following location.
CSS Location: C:\Program Files (x86)\Syncfusion\Essential Studio\13.1.0.21\JavaScript\assets\css\web
Script Location: C:\Program Files (x86)\Syncfusion\Essential Studio\13.1.0.21\JavaScript\assets\scripts\web
Please refer the below Online Documentation link for creating a sample in ASP manually.
Online Documentation link: http://help.syncfusion.com/ug/js/default.htm#!documents/createmanually1.htm
For your convenience we have created a simple sample binding 2000 records to grid and displaying the grid without paging. The sample can be downloaded from the below location.
Sample Link: Sample.zip
Please try the above sample and if you are still facing the issue, then please get back to us with more information such as any script error thrown or reproduce the issue in the above sample if possible.
Regards
Gowthami V.