HandbookReference

Troubleshooting

Something does not work as expected? Find the symptom below: each entry says what is behind it and what to do. If yours is not here, the last section says how to report it.

Installing and the first start#

Windows says “Windows protected your PC”#

Cause: Windows SmartScreen warns about programs it has not seen often. The installer is code-signed from version 0.9.9, but a new certificate has no reputation yet; older versions were not signed.

Fix: Choose More info, check that the publisher reads Open Source Developer Jonas Harth, then Run anyway. Download the installer only from this website or the GitHub release. See Install PrismLCA.

The AppImage does not start on Linux#

Cause: A downloaded file is not executable until you allow it.

Fix: Make it executable once with chmod +x PrismLCA-*.AppImage, or allow it in the file's properties dialog of your file manager.

“Download failed” for the search model#

Cause: On first start PrismLCA downloads its search model, about 2.3 GB, from huggingface.co. The dialog shows why the download failed — usually no internet connection, a firewall or proxy that blocks huggingface.co, or too little disk space.

Fix: Solve the cause the message names and choose Retry. Check that you have several gigabytes free. Quit closes PrismLCA; the next start asks again. PrismLCA cannot run without the model.

PrismLCA stays on the splash screen#

Cause: The splash screen waits while PrismLCA starts its calculation engine. The first start takes longest.

Fix: Give it a minute. If it never finishes, close PrismLCA and start it again. If that does not help, reinstall — your workspaces are kept in a separate folder (see Where your data lives) — and report the problem with any message you saw.

Importing background data#

The import stopped, and nothing was imported#

Cause: An import is all-or-nothing: if exchanges or characterisation factors cannot be linked to an elementary flow, PrismLCA writes nothing rather than half a database. Almost always, files from two different ecoinvent releases were mixed — the datasets folder, the master data beside it and the LCIA Implementation workbook must all come from the same release.

Fix: Read the message: for a characterisation factor it names the flow it looked for and the closest matches, which usually points to the odd file out. Extract all files of one release again and start the import again. See Background databases.

The import takes very long, or the computer becomes slow#

Cause: Importing ecoinvent is heavy work. It takes several minutes and needs about 6 GB of memory at its peak.

Fix: Let it run and close other memory-hungry programs. After the import, the search index is built in the background; the search panel shows its progress.

No impact methods, and nothing can be calculated#

Cause: The inventory was imported without the LCIA Implementation workbook, so the workspace has datasets but no impact methods. The Calculate button then says No LCIA methods installed yet (import ecoinvent).

Fix: Open OverviewBackground, choose Add impact methods… and pick the LCIA Implementation workbook of the same ecoinvent release. Nothing has to be imported again.

Searching and modelling#

Search finds nothing#

Cause: PrismLCA searches with an index it builds on your computer. Right after an import the index is still being built — the search panel shows Indexing… with a count — or a database is not indexed at all, and the panel says that nothing from it can be found yet. Two other causes: the database is not ticked in the search panel, or a filter (type or region) excludes every hit.

Fix: Wait for Indexing to finish (for a full ecoinvent one to two hours; the panel shows the time left), or choose Index for a database that has none. Check the database ticks and clear the filters. See Find the right dataset.

The Calculate button is greyed out#

Cause: On the canvas, Calculate needs exactly one selected process as the functional unit — its tooltip says Select one process as the functional unit. On the Results page it needs a subject and an indicator: Pick a subject and an LCIA indicator first.

Fix: Click the one process that delivers your functional unit, then Calculate. On the Results page, pick at least one subject and one indicator. See Calculate.

The results did not change after I edited the model#

Cause: Results are never recalculated on their own.

Fix: Choose Calculate again. On the Results pages a banner says when the selection or settings changed after the last calculation.

I cannot edit a background process#

Cause: Background datasets are read-only on purpose; on the canvas they are references.

Fix: Right-click the process and choose Localize (edit) to get an editable copy in your model. See Build on the canvas.

I cannot type a unit like “bottle”#

Cause: Unit fields accept only known units by default, to keep typos out.

Fix: Turn on SettingsModellingAllow free-text units.

The AI assistant#

The chat field is greyed out#

Cause: If it says No OpenRouter API key configured — add one under Settings → AI., there is no key; if it says Open a model to chat, no model is open.

Fix: Enter a key under SettingsAIProvider, or open a model. The assistant is optional; everything else works without it. See Set up the assistant.

“API key invalid or missing”, “credits exhausted”, “quota exhausted”#

Cause: These messages come from your provider, not from PrismLCA: the key is wrong or revoked, or your account has no credit left.

Fix: Top up your credit at openrouter.ai, or under platform.openai.com → Settings → Billing for OpenAI. Or paste the key again under SettingsAIProvider; the field shows a short mask of the stored key, which is the quickest way to spot a truncated paste.

“No provider is available for this model” or “All providers have been ignored”#

Cause: OpenRouter found no endpoint it is allowed to use for this model. There are two possible causes, and the message names them:

  1. PrismLCA's privacy switch. Only use providers that keep nothing (zero data retention) restricts requests to endpoints that retain nothing, and some models have none.
  2. Your OpenRouter account's own privacy settings. If you excluded providers or disallowed some data policies at openrouter.ai/settings/privacy, no setting in PrismLCA can widen that. A model served by a single provider becomes unusable as soon as that one is excluded.

Fix: First, under SettingsAILimitsPrivacy, exempt the model's vendor or switch zero data retention off for a moment and try again. If the error stays, allow the provider in your account at openrouter.ai/settings/privacy — or pick another model.

“Rate limit reached”#

Cause: The provider is limiting how fast you may send requests.

Fix: PrismLCA already retries on its own. If the message stays, wait a moment and send your message again.

“Request too long for this model's context window”#

Cause: The conversation, with everything the tools returned, no longer fits into the model.

Fix: Start a New chat and give it a short summary of where you are, or pick a model with a larger context under SettingsAIModels.

The assistant stopped: “the cost limit … was reached”#

Cause: The run spent as much as Cost limit per run ($) allows ($15 by default). This is the brake working, not an error.

Fix: Choose Continue. The first click names the amount it will allow — Spend up to another $… — and the second click goes on. To change the limit for later runs, see SettingsAILimits.

“OpenRouter unreachable” or “OpenAI unreachable”#

Cause: PrismLCA could not reach the provider — no internet connection, or a firewall in the way.

Fix: Check your connection and try again.

External agents (MCP)#

My agent does not see PrismLCA, or every call fails#

Cause: Most often the client has not re-read its configuration, the MCP switch is off, or the client's entry points at an older PrismLCA installation.

Fix: Check that Let external agents drive PrismLCA (MCP server) is on, choose Test connection, and restart the client. After an update, or after moving the AppImage, use Reconfigure… for that client. The agent's error message usually says which of these it is; Connect your agent lists them one by one.

The agent says it is waiting for my answer#

Cause: It asked a question or needs your approval in the PrismLCA window.

Fix: Look for the bar … is waiting for your answer. under the toolbar and choose Answer. A card waits up to 15 minutes. See Stay in control.

Report a problem#

If your problem is not on this page, please tell us. Every report makes the next version better.

  • What you did, step by step.
  • What you expected, and what happened instead — with the exact error message, or a screenshot.
  • Your PrismLCA version, shown under SettingsAbout, and your operating system.

Open an issue on GitHub — the welcome tour's last card links there too — or, without a GitHub account, send it through the contact form. Feedback and feature requests are welcome in both places.

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