Is this a remote engine service, or a local engine?

I think Higher upgrade should be able to open lower files

Local engines. I haven’t messed with remote engines, so that distinction wasn’t apparent.

And just to be clear, it’s not as if Flow doesn’t know the version (build number) of the engine(s):

Anyone from Safe Software want to weigh in on this issue ?

So, I upgraded my Flow to 2025.0.3 and my Form to 2025.1.1

It seems I can now upload workspaces, although I get a warning about versions. This is good.

I then did an engine update to 2025.1.1, but I still get a version warning, referring to the Flow GUI version, not the engine version.

Is there a reason for issuing a warning when the Form version doesn’t exceed the engine version ?

Anyone with Safe want to dive into this issue ?

This is not an issue, FME Flow doesn’t support separate engine upgrade (or its very limited to the major version you’re using : https://docs.safe.com/fme/html/FME-Flow/AdminGuide/Upgrade_FME_Engine_Only.htm). So you’ve done that at your own risk. You have to use the engine installed with your FME Flow version.

Your FME Flow and FME Form must be at the same version. If not, inconsistent behavior might happen (troubles with uploading your workspace, incorrect definition of services, not be able to commit,...)

“Is there a reason for issuing a warning when the Form version doesn’t exceed the engine version ?”
Yes, because FME Form talk to the FME Flow Web UI to publish the workspace, not the engine. FME Flow Web UI has its own API that’s used by FME Form and evolve with versions, and so unexpected behavior might happen if the version differs.

Of course engine upgrades only apply within the same major version (2025, 2024 etc.). This is not the issue here.

If engine upgrades are not supported, as you’re quite adament about, why is the “engine only” download then even available ? The document you refer to states that engine updates _are_ supported.

It does however state that X.0 to X.1 are not supported, but I’m pretty sure, that it works, and that the problem with versioning is the same.

In general, insisting on full Flow updates instead of engine updates is not sensible. You incur more downtime and more resources in a production environment. This is only sensible in test and development environments.

“FME Flow supports installing newer FME Engines if those engines share the same version year and major point (yyyy.x) version as the current installation of FME Flow. The same guidelines apply to installing newer FME Engines on Remote Engines Services. That is, the newer engines must share the same version year and major point version as the primary FME Flow installation.”

Major versions are 20XX.YY. eg. FME 2025.0 is a major version, FME 2025.1 is another one.
So Safe Software is telling here that you should be able to install an FME Engine 2025.0.1 on a FME Flow 2025.0.0. But not an 2025.1 engine on 2025.0 Flow.

Also, since FME 2025.1, there was a major update on the API side of FME Flow, and the API v3 that was used by older clients (like FME Form 2025.0) has been deprecated. So Form 2025.0 might have issue while publishing on Flow 2025.1, and vice versa.