Configuration and Installation

I haven’t been able to find any articles about this issue so I hope it is OK to ask a question here.  I have a sandbox running 2019 R1 19.120.0012.  I updated this site a few weeks ago using the Apply Updates option in the System Management area.  When I try to use the Configuration Wizard to update the database it gives me the following error: Upgrade process has been interrupted. The database cannot be upgraded because your current build (19.120.0012) is incompatible with the build (20.200.0077) you want to install. Wait for the next update package that will be compatible with your current build.The call stack indicates that the installer doesn’t seem to know about 19.120 release. at PX.BulkInsert.Installer.InstallationCommon.IsAllowToUpgrade[t](String currentPrintVersion, String installerPrintVersion, List`1 KnownVersions)   This seems to validate what the 2020 R2 release notes say about the direct upgrade path from 2019 R1 to 2020 R2:Acumatica ERP 2020 R2 can be upgraded from the f

Can someone help me out with is. How can we solve this.

When we use the tool in the Acumatica Partner Portal to request a sandbox for upgrading a SAAS customer, can we upgrade more than one major version (ie from 19.1 to 20.1)?  We recently used the tool to create an upgrade sandbox but found that we could only upgrade on version at a time.  Is it only possible to create a sandbox for upgrading more than one version by filing a support case?  If our customer is moving up two version we don’t want to have them go through the upgrade process twice.

I have a client who works for companies like the Department of Defense, various law enforcement agencies, etc.  As part of doing business with them, my client is required to provide a Disaster Recovery Plan of their systems.  Since they are a SaaS client we need this information from Acumatica.  I have found, or have been given the marketing documentation on the website and portal, but we need a formalized plan.  Can you provide us the location or a copy of this document?