A platform event message failed to start the "B2C Commerce: Platform Event: Process Contact Update" flow

[igor-epam]

Hello,

While creating account on Ecom (Commerce Cloud site) we are getting following error email message (in Service Cloud):
A platform event message failed to start the "B2C Commerce: Platform Event: Process Contact Update" flow. Contact Salesforce Customer Support with error ID 2039125901-292848 (1002773884).

You’ve received this email because an error occurred while your "B2C Commerce: Platform Event: Process Contact Update" flow was running.
Error element ia_retrieveB2CCommerceCustomerProfile (FlowActionCall).
An Apex error occurred: System.CalloutException: You have uncommitted work pending. Please commit or rollback before calling out

Any idea why I'm getting this error?
Thanks.