If I reopen a scene with dynamics I get the following warning. I'm using houdini 9.1

This means that Houdini has gone through some changes since the last version of Houdini that you had installed, and that some of your nodes had to be changed to compensate.

Probably nothing to worry about, though good housekeeping would be to go in and recreate those particular nodes if you can.

Well, these files are not from an previous version of houdini. I only work with houdini 9.1, nothing else. Okay, I have installed 9.0 on my disk, so maybe houdini has problems with this configuration.

It's related the the particular release of houdini that you saved that file with. So if you last saved it with 9.1.100 and you loaded it in 9.1.101, it's possible that something like this can happen(it's still in beta and things get tweaked). Having 9.0 on the same system is OK and won't affect this.

Cheers,

J.C.

All is done in H9.1.95, no other version was ever used for saving or loading the scene. Anyway, it seems not to affect my scenes.