PhpStorm 2025.x upgrade rollback: restore the previous config directory or reimport settings from scratch?

Short answer

Restore the previous version's config directory wholesale. That is the lower-risk path in the normal case, because a new PhpStorm major version creates its own version-specific config, system, and plugins directories and imports settings from the old one by copying, not by rewriting it in place. Reimporting an exported settings archive into a fresh config is the fallback for the unusual case where you know the old directory was touched — and it loses more state than most people expect.

Why the old config directory is usually intact

PhpStorm separates its state by release: the config directory (settings, keymaps, code styles), the system directory (caches, indices, local history), and the plugins directory are all namespaced per version. On first launch, the newer build offers to import settings from the previous version's directory; that import reads the old directory and writes into the new one. The old build can therefore still be launched against its original, untouched config. Toolbox retaining earlier builds under \"Other versions\" makes the binary downgrade independent of this decision — old build plus old config is the coherent rollback unit.

When the fresh-reimport path is the right call

The contamination scenario you describe is real only if the new build was pointed at the old directory directly — for example via a custom idea.properties file overriding idea.config.path/idea.system.path, or a manually shared path. In that case the newer build may have migrated files in place, and reusing the directory becomes risky. If you never overrode the default paths, assume the old config is clean.

What each approach preserves

On plugin compatibility

Reusing the old directory is actually the safer option here, not the riskier one. Plugin directories are version-specific, so the rolled-back build sees the plugin versions it originally ran with. The failure mode to watch is the reverse: a fresh config that re-downloads plugins may fetch builds requiring the newer IDE. After rollback, open Settings > Plugins and confirm nothing shows an incompatibility warning.

Practical rollback sequence

1. Before upgrading (or now, if not done): confirm the exact config/system/plugins paths for your version — they differ by OS (e.g., under ~/.config/JetBrains, ~/Library/Application Support/JetBrains, or %APPDATA%\\JetBrains) — and copy them somewhere safe. Also export a settings archive as insurance.
2. In Toolbox, install the previous build from \"Other versions\" and launch it.
3. Verify it is using the intended config directory, then open a known project and check that local history entries and run configurations appear.
4. Check Settings > Plugins for incompatibility warnings.

Caveats

Exact paths and import behavior should be confirmed against the documentation for your specific release, and this guidance assumes default directory locations. If you did customize idea.properties or share paths between versions, say so — that changes the recommendation toward the fresh reimport.