You have a workspace with a linked custom transformer (version 1). The author of that transformer makes a series of edits and updates it to version 4. What do you think the upgrade option does to the custom transformer in your workspace?

• A. Upgrades it to version 2
• B. Upgrades it to version 3
• C. Upgrades it to version 4
• D. It depends on what version of FME you and the author are using

Answer: (C)

In FME, a linked custom transformer carries its own version history. When the author updates that transformer and publishes a newer version, the consuming workspace can upgrade the link to use the newest published version. The upgrade operation doesn’t just move to the next numbered version; it pulls the latest version available for that transformer.

Since the author has advanced the transformer to version 4, upgrading the linked transformer in your workspace will switch it to that latest version, bringing in all changes from version 4. The upgrade is about the transformer's version lineage, not a fixed next step or a dependency on your own FME version (as long as the newer version remains compatible). So the upgrade results in version 4.