Cross Site Colum error on large list - maxJsonLength Exception

[Matthias]

I have an issue with cross site lookup column when trying to look up items on a list with 56.000 items.
The SharePoint settings for ressource throttling of the web application are already set to 60.000 and the lookup list is accessable via browser.

After adding a cross site lookup column to my target list I cannot open an item display form in the target list any more.


In SharePoint Log I find this message:

System.InvalidOperationException: Error during Serialisisation or Deserialisation with JSON-"JavaScriptSerializer".
The length of the string exceeds the value of the maxJsonLength-property.

Some research on google told me to change the maxJsonLength property in web.config settings in IIS Web Application, but without succeess.

The most detailed description and a workaround can be found here:
https://social.technet.microsoft.com/Fo ... is-ignored


Is this adaptable to the Cross Site Lookup Cloumn?

[Matthias]

Additional notes:

I found out that this behavior only appears when using Cross-Site-Lookup in Standard SharePoint list forms.
As soon as the form is replaced by a plumsail form the error disappears.

[Dmitry Kozlov]

Hi Matthias,

Thank you for the issue report. I don't believe that it is caused by the Cross-site Lookup because SharePoint renders it on a display form absolutely the same way as out-of-the-box lookup. It even doesn't contain any server-side logic. You could verify this by adding an out-of-the-box lookup field and configuring it to get data from your large list. But Forms Designer allows you to workaround this problem because it renders the Cross-site Lookup as a simple input field and loads data in portions on the client-side.