A Flatpak app’s required runtime is unavailable · Linux Fix Lab

Symptoms & scope

Flatpak reports a runtime ref that is not installed.
The same runtime ID exists only for another branch or installation scope.

Relevant environment

Flatpak user and system installations; apps can require different branches of the same runtime ID.

Recognizable messages (synthetic examples)

error: runtime/org.example.Platform/x86_64/1.0 not installed

Compare full ref and installation scope; this is not proof that no remote publishes it.

error: No remote refs found similar to 'org.example.Platform//1.0'

Check spelling, branch, architecture and remote scope; this can refer to apps as well as runtimes.

Possible causes

These are possible explanations, not a confirmed diagnosis. Several independent faults can coexist.

The app’s exact runtime ref may be missing after an incomplete installation.
The app’s origin remote may be disabled, absent in the relevant scope or no longer publish that branch.

Diagnose safely

Run one command at a time in the relevant session. Read the explanation first. Uppercase placeholders need your own values; tools and privileges vary by distribution. These commands are displayed here and never executed by the website.

Check 1

Replace APP_ID with the affected installed application; add --user or --system if the ID exists in both scopes.

flatpak info --show-runtime APP_ID

Interpret the result: Record the full runtime ID/architecture/branch. A runtime with the same ID but a different branch cannot automatically substitute.

Check 2

Lists installed runtime refs and their origin/installation without installing or repairing them.

flatpak list --runtime --columns=ref,origin,installation

Interpret the result: Compare the exact ref and scope with the app. Presence in another installation does not prove the app’s dependency resolution will use it.

Check 3

Reads configured remote URLs, options and scopes. It does not add a remote or install metadata.

flatpak remotes --show-details

Interpret the result: A disabled or wrong-scope origin supports an installation-source issue; the configured URL alone does not prove the branch is still published.

Evidence-guided next steps

Install the exact runtime through the trusted app origin

If the app origin still publishes the required ref, install or update through that trusted remote in the app’s intended installation scope so Flatpak resolves its declared runtime. Inspect the runtime ID, architecture and branch in the proposed transaction before accepting.

Precautions: Do not add an unverified remote or force an unrelated runtime branch. Keep the app’s data directory and previous commit information.

Recovery / rollback: Remove only the newly added runtime when no installed app requires it; restore the saved compatible app/runtime snapshot if a version change must be undone.

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Use an app release based on a maintained runtime

If the required branch is no longer published or supported, obtain the maintainer’s supported app update that declares a maintained runtime. Preserve application data before migration and keep installation scope explicit; do not rewrite the app’s runtime metadata manually.

Precautions: A newer runtime by itself cannot fix an app built for another ABI. A no-ref error may also be a typo or wrong remote, so verify that first.

Recovery / rollback: Restore backed-up app data and the previous compatible supported app/runtime versions if available; do not remove all old runtimes blindly.