You have to say what the problem is. We need both pieces of information on this page:

https://www.zotero.org/support/reporting_problems

[JavaScript Error: "item ID '6708' is not an integer (string)" {file: "chrome://zotero/content/xpcom/data/dataObjects.js" line: 178}]

[JavaScript Error: "'title' value cannot be undefined" {file: "chrome://zotero/content/xpcom/data/item.js" line: 615}]

But based on this, you should 1) restart Zotero and 2) database integrity from the Advanced → Files and Folders pane of the Zotero preferences.