Troubleshooting
Empty results, rejected jobs, stuck queues, invalid SMILES.
Things go wrong in four common ways. Here's what each one looks like and what to try.
Empty results (no routes found)
The model searched but could not find confident retrosynthetic routes for your target. This does not mean the molecule is unsynthesizable — it means the model's training data does not contain sufficiently similar transformations to propose a route it trusts.
Rejected submission
A Rejected status means the request was not processed, usually due
to a server issue rather than a problem with your molecule. Common
causes include missing stock files or temporary server load.
Job stuck in "Queued"
Jobs process sequentially — if you submitted multiple jobs (especially via "Try All Lengths"), they run one at a time. Longer step counts take more time: a 3-step job typically takes 1–2 minutes; an 8-step job takes 5–10 minutes. The page auto-refreshes every 15 seconds.
SMILES validation error
If the SMILES input shows a red error, the molecule string is invalid. Common issues: unmatched parentheses, unclosed brackets, invalid ring closure numbers, or unsupported characters.
What to read next
- Submitting your first retrosynthesis — the standard happy-path submission flow.
- Retrosynthesis search — every parameter and what it does.