This past week I was asked if it was possible to upgrade a very early version of Sage 100 (previously known as MAS 90 or MAS 200) from a level as early as 3.71 to the current version which is Sage 100 2019.
In short, the answer is yes – although the Sage 100 v2019 Customer Upgrade Guide states that you must first be at version 3.71 and then migrate to 4.50 Product Update 8 and then to the latest Sage 100 release.
The interim stop at version 4.50 Product Update 8 seems to be required for certain third-party solutions as well as a reqirement by Sage.
You should plan to migrate to 4.50 PU 8 and then onto the latest Sage release.
Sage 100 4.50 Product Update 8 is available from the Sage KB