Error 2146827859 when importing from Synergist

SOLVED

We have three companies in Sage 50cloud Accounts Professional.  Two were set up some time ago, and the third one in the last year.  We import purchase invoices from a third party programme called Synergist which also has three companies to match Sage, and this works fine for the first two companies, but when trying to import from the third we just keep getting the message:-

B4D_RunScript - Failed to run script: Sage2.VBOLE

Error code:-2146827859  Line No:51  Char-2

Description: ActiveX component can't create object: 'SDOEngine.27'.

Set oSDO - CreateObject(cEngine)

Then a message that says:

**Batch ....... - UHNANDLED EXCEPTION FROM SAGE.  PART POSTING OF BATCH MAY HAVE OCCURRED.............  

... which I don't think is the issue, but suggests the problem lies within Sage. 

In the old days when we had similar issues we following advice, but under V27 this option has disappeared 

https://synergistexpress.zendesk.com/hc/en-gb/articles/115005806669-Method-Exception-Sage-Data-Objects-Sage-Data-Objects-Registration-error

All the settings in both systems seem fine, so I can't work out why we are hitting a wall on this one - any ideas happily received?

Thanks