While using VCC Salesforce integration, the VCC user gets a pop-up error:
Your CRM vendor has returned am error: "unable to obtain exclusive access to this record."
Virtual Contact Center Salesforce integration users
8x8 Engineering has not identified an issue with the VCC Salesforce integration. Please have your Salesforce administrator enable or confirm user permissions within Salesforce for lead or an other entity. It is also recommended that Windows 7 users get upgraded to Windows 10.
This may be related to Salesforce users not having permissions within Salesforce for lead or any other entity.
Please also review the Salesforce forum article for other possible causes: