In prior versions of Sage 100, it was common when undergoing an upgrade final conversion to copy the main company data file – MAS_XXX from the old version of Sage into the newer version.

For the first conversion, the data would be migrated as per Sage instructions. Then, typically, some testing happened for a few days. When ready to perform a final data conversation sometimes the data folder could be copied and converted as opposed to going through another migration and conversion.

System migration can be time-consuming and potentially created issues (ie – overwrite) with forms or panels that were modified in the upgraded version.

Once the data was copied the final conversion could occur without a lengthy re-migration.

Certain features such as Paperless required some behind-the-scenes work to synch, however that was a task many consultants were comfortable performing. Similar workarounds exit for copying SageCRM data.

With version 2018 Sage has issued this update which advises AGAINST copying the MAS_XXX.

The encryption key is invalid. See your system administrator.

Cause
Copying MAS_XXX (XXX=Company Code) data into the MAS90 folder of Sage 100 2018 installation.

Installing Sage 2018 in the same location as any prior installation and not removing the MAS90 folder prior to the installation.

Resolution
Remove the MAS_XXX folder that was copied into the Sage 100 2018 Mas90 directory.
Do NOT copy only MAS_XXX data under the MAS90 directory as done in 2017 and prior versions. Due to the encryption in version 2018, this will not work. Must also copy MAS_System folder when attempting to bring data into version 2018.

Uninstall the Sage 100 2018, remove the MAS90 folder and anything in it prior to reinstall.

Do NOT install version 2018 over an existing MAS90 directory from a prior installation.