Communication Link failure in OpenOffice

Hello,
When I am working on an OpenOffice document file, an error message suddenly appears.
The message says that the link of communications fails because the connection is refused.
Please find below the screenshot of the error message for your reference.
Could any expert help me to solve this issue please?
This matter is quite urgent because I have to finish my project paper by next Monday.
Thank you for your attention.
openOffice.org Base
Communication link failure due to underlying exception:
**BEGIN NESTED EXCEPTION**
Java.net.connectException
MESSAGE: Connection refused
