Why Dash made in old libraries does not work on recent libraries?

I have developed Dash App using the libraries versions:



If I use upgraded libraries as existing now, my App gives never ending errors, you correct one, appears another but if I downgrade to old versions, it runs flawlessly.

There are not going to be large breaking changes after Dash 1.0.0. Before that, it was still in development. There were many breaking changes between 0.20.0 and 1.0.0.

Right - we take semver seriously, so we tried to be foresighted and pack in all the breaking changes we needed into the 1.0 release - I assume you’ve seen the migration guide here: https://dash.plot.ly/dash-1-0-migration - and unless and until we make a v2.0 (which we do not have any plans to do) there will be no more breaking changes.

But since we were still on 0.x until that point, there were a number of breaking changes in the minor releases between 0.20 and 0.43 (the last pre-1.0 release) that unfortunately aren’t captured in the migration guide - for those your best bet is likely the changelog

I promise you there is an end to the errors - I’ve personally upgraded some large apps for our clients over about the same version range, and it’s not quick but it’s doable!

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