Does this mean that the error occurs during opening of the workflow, i.e. without trying to execute the node? Can you try to reset the workflow before saving it?
Apart from that, you can also try to increase your database timeout by going to File -> Preferences -> KNIME -> Databases and change the value there.
Apologies for my delayed response I didn't get a reminder that someone had responded (thanks for your comment)
I did try increasing my database timeout (not concrete effect on connecting)
I also did try resetting the node and or workspace, that works about 50% of the time, which is the issue I don't know what causes this no repeatable performance. A few of my colleagues have the same issue and are trying to find out why the connection to Access is so unstable.
If you know anything else I can try it would be appreciated, thanks in advance!