Item in SharePoint list does not open

[João_Caetano]

I have a list in SharePoint, used for contract management, with many fields, but recently I came across an error when trying to open one of the list items, it does not open and displays this message "Error during serialization or deserialization using JSON JavaScriptSerializer . The length of the string exceeds the value defined in the maxJsonLength property.", I tried to retrieve the data for this item using a stream in Power Automate but the attachments saved in it could not be accessed, does anyone know how to solve this?

[#2 · Accepted solution]

@João_Caetano 

The error message you are encountering, "Error during serialization or deserialization using JSON JavaScriptSerializer. The length of the string exceeds the value defined in the maxJsonLength property," indicates that the data associated with this particular SharePoint list item is too large to be serialized or deserialized as JSON. This can happen when there is a large amount of data or complex data structures in that item.

To address this issue, you can try the following steps:

1. Check the Item Content: First, review the content of the problematic list item to see if there is any particularly large or complex data, such as very long text fields, attachments, or multi-valued lookup fields. Reducing or simplifying this data could help.
2. Break the Item into Multiple Items: If the item is too large due to a high number of attachments or other factors, consider breaking it into multiple smaller items. You can create a new item for the additional data and link it back to the main item using lookup fields or relationships.
3. Archiving Attachments: If attachments are a significant part of the issue, consider moving attachments to a document library or a separate storage location and then link to those documents from the list item instead of including them directly as attachments.
4. Power Automate: When using Power Automate, you can retrieve the data incrementally. Instead of trying to get all the data at once, you can fetch specific fields or sections of data as needed, which can help you work around the JSON serialization limit.
5. Increase the maxJsonLength Property: If none of the above solutions work, you can increase the maxJsonLength property limit in your SharePoint Online environment. However, this should be done cautiously as it can have performance implications and isn't recommended unless absolutely necessary. You would typically do this through SharePoint Online Management Shell, but it might require administrative privileges.

Remember to back up the problematic list item and its data before making any changes.

My knowledge of this topic is limited, but since no one has answered it for at least one day or more, I entered your question in various AI. The text and the steps are the result of various AI's put together.

My answers are voluntary and without guarantee!

Hope this will help you.

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