If you have a back up copy of the 2011 version of the Sage 50 file you should be able to restore it directly in the 2018 version with a couple of points to watch. You must have 2015 installed on the computer with the 2018 program. You do not need to restore the file in the 2015 version first. The 2018 program will use files from the 2015 version in the process but it is a part of the programming. The other point to watch is that you are matching the same edition or higher when restoring.   Pro, Premium, Quantum  The very basic edition, First Step, does not always convert easily when jumping over many years. 

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Thanks for reaching out!  Have you done all of your Windows updates? If it's Windows 10, then check the blog below with more details about firewalls, etc. Should the issue persist, please contact the Technical Support Team at 1-888-522-2722.

I found an article in our knowledgebase that should answer your question. Please click on the link below to access to it and review.

Articles: Error: "Sage 50 cannot open the database because the database engine reported an error" when trying to open my Sage 50 file

Regarding firewalls and program blocks, please see Steps 1 to 4 about: How to get Windows to trust Sage 50 and other programs?

Please also review the Top Windows 10: Troubleshooting Tools to Use!

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