Cannot create Search Index; form not correctly rendered

We are unable to create a new search index for our site.
It seems like the config page (where content items to be indexed can be chosen) is not rendered correctly, resulting in not being able to add a search index.

We have four custom modules (created with the Module Builder).
The problem cannot be reproduced by creating a new project and import the custom modules build in the former project. Also after applying the same language settings (NL-NL) the problem cannot be reproduced.

Sitefinity version 5.1.3210.0.

Please see the attached images for the incorrect and correct config windows.

Does anyone have any idea what the problem could be and how to fix it?

Hi,

We have tried to reproduce this problem but without success. Would you try to clear the browser cache and delete the asp.net temporary files? If the problem still exists would you open a ticket and send us your project in order to investigate the problem further?

Regards,
Ivan Pelovski
the Telerik team

Clearing cache and temporary asp.net files did not do the trick.
I have opened a support ticket: 571307

Hi,

Thank you for the additional information. We have sent you a response to your ticket.

All the best,
Ivan Pelovski
the Telerik team