Why do some developers break their own compatibility???

[Trancit]

I noticed this with Spire and Synthmaster... perhaps there are some more...

I got here some demo projects, which require Spire 1.0.20... I have the actual version installed and the host doesn´t find it... it´s not able to load the plugin...

Same for Synthmaster... made some patches for an older version and saved them in a host specific format...
I cannot load them with the actual version because of a different plugin id...

TBH: WTF!!!!

And honestly I don´t understand the reason why this should be necessary...

[Zexila]

Things changed under the hood and that's the only way to have backwards compatibility with older projects, because new version of same plugin sound different on same settings.

[chk071]

Yes. Although, in the case of Spire it's rather a case of "1.1 versions COULD sound a bit different". I never really actually noticed a difference.