The error “This entity is read-only” can occur due to several possibilities: 

• You could be trying to open an archive company
• You could be using a product on subscription whose license was not renewed and has expired.
• You could be using a company that has Sage Drive active and their product is not on a current plan
• You could be using a company with has Sage Drive, but the company has been paused

If none of the above resolves the issue, we can investigate further but it would require a subscription to our Developer Partner Program. Please send your contact details to [email protected] and we will start the application process. Thanks!

I am receiving this exact error after updating to the latest version of Sage 2021. The same exact code was working prior to upgrading. Any help is appreciated. Thanks!

Sage support was no help! I uninstalled all sage products, cleaned out my registry of all sage settings. Install Sage 50 and a new sample DB. Then all worked. I got the same reply from them and their knowledge db had similar but all to no help.

Another possibility is that your support plan may have expired or not activated. You can find this at the Help -> About Sage 50 Accounting Screen. If the Plan Level field shows 'None' or an invalid entry then you need to get it fixed. Thanks!