This Error Number 8205 is a HMRC data validation message relayed back from the HMRC server. , the software is simply displaying the message received from their servers and giving you advise of what you can check. Please note, the issue has nothing at all to do with the software and you should refer such queries to HMRC. HMRC staff you spoke to should have been able to help you as the error relates to their server response received when you are submitting the returns.
As the HMRC server validation error suggests, the UTR (Unique Tax Reference) you have entered for one or more Partners you created within the partnership statement is incorrect, hence HMRC are rejecting your submission. Enter the correct UTR and resubmit.
If the problem persists, please contact the HMRC Online Services helpdesk on Tel 0300 200 3600.
Disclaimer: We cannot advise on how you should complete your tax returns or how the taxes are calculated. Information provided here is given without any obligations and we will not accept any claims or liabilities for any damages as a result of you relying on the information given here, if in doubt you must consult the HMRC Online Services Helpdesk on 0300 200 3600.