Common problems
What the messages you are most likely to see in a Phases conversation mean, and the concrete next step for each one.
Most of the moments where Phases appears to be stuck are deliberate. It refuses to guess a material, refuses to treat a chemistry you typed as calibrated, and refuses to report a result it did not actually compute. The entries below are ordered roughly by how often you will meet them.
It asks me which material to use instead of running the simulation#
What it means — There is no default material in Phases. A request such as "run a simulation", "generate CCT", or "simulate welding" that names no grade, no chemistry, and has no material already active in the session gets a question back. The rule is enforced twice over: the agent will not call a simulation tool, and the tool itself answers "Please choose a material before running a simulation. Examples: DC04, DP600, 22MnB5, EN13261, a workspace material, or a custom composition."
What to do — Name the material in the same sentence as the simulation:
Generate a CCT diagram for DP600 and find the critical cooling rate for full martensite.
You can also load a material first and then ask for the run — once a material is active, later simulations in that session use it without you repeating it. See Material catalog.
It asks me to confirm a chemistry before doing anything#
What it means — Any composition you supply or change is treated as uncalibrated. Instead of creating the material, the tool returns a confirmation request naming the closest catalog grade and saying that its stable material definition and compatible base-card template can be saved now, and that each simulation will resolve only the physics it needs and report unavailable or fallback states explicitly. Nothing exists yet at that point.
What to do — Reply that you want to continue, or adjust the numbers and let it re-check. Confirming stores a stable definition and a compatible base card only — it does not calculate transformation kinetics, phase flow stress, or a V-Gleeble flow surface. Each simulator resolves what it needs afterwards, and may still report that something is unavailable. See Your own chemistry and The capability matrix.
I have run out of free messages#
What it means — Without signing in you get a limited guest allowance, five messages in a 24-hour window by default. A counter warns you as it runs down; when it is gone, a banner invites you to sign in to continue the conversation and save your history, and the send button is disabled. The allowance is spent when a message is accepted, so a turn that errors still costs one.
What to do — Sign in or sign up from the buttons in that banner. Signed-in users are not metered by the guest counter, and they also get chat history, the run browser, and the simulation panel. See Guests and limits.
"Another chat turn is still running"#
What it means — One session runs one turn at a time. A second submission while a turn is active is rejected before anything executes, and the browser shows "Another chat turn is still running. Wait for it to finish, then retry." Nothing was started by that click, so nothing was duplicated.
What to do — Wait for the current turn to finish, then resubmit. If you clicked Run Simulation on a parameter card, the card is restored so you can submit it again. See How the conversation works.
RSW will not accept my steel grade#
What it means — Spot welding needs validated bulk electrical, thermal and mechanical property data, and only twenty grades have it: DC01, DC03, DC04, DC05, DC06, HC260LA, HC300LA, HC340LA, HC380LA, HC420LA, DP450, DP500, DP600, DP780, 20MnB5, 22MnB5, 20MnB8, 25MnB5, 29MnB7 and EN13261. Anything else is rejected before the solver starts, with a message naming the parameter and listing the supported grades. Being in the material catalog does not imply an RSW mapping.
What to do — Pick the closest supported grade, or run your chemistry on one of those base grades: the plate grade selects the property family and your composition rides along with it. For an unsupported steel such as AISI 4140, load the chemistry and let Phases tell you what it is closest to. See Resistance spot welding.
"Required material physics is unavailable"#
What it means — Each simulator declares which material capabilities it needs, and refuses rather than substituting something weaker. The message names the operation — for example "Required material physics is unavailable for V-Gleeble hot_tensile" — and the tool card adds a second line, "Missing capabilities:", listing what could not be resolved, such as transformation kinetics or bulk flow surface.
What to do — Check what the operation requires. Heat treatment and CCT need a base card plus transformation kinetics; the V-Gleeble deformation modes (hot tensile, hot compression, Satoh) additionally need a validated bulk flow surface, which an arbitrary custom chemistry does not have. Running the same study on a built-in grade is usually the fastest way to confirm that the material, not the setup, is the blocker. See The capability matrix and Virtual Gleeble.
The results do not look right#
What it means — Usually one of three things: an input that was read differently than you meant, an imposed initial condition, or a documented model limit. Two input traps are worth knowing. Heat-treatment curve temperatures are auto-detected by magnitude — a peak at or below 1000 is read as Celsius, above 1000 as Kelvin, so writing 1100 for 1100 °C is interpreted as 1100 K, about 827 °C. And CCT imposes a fully austenitic start rather than simulating the heat-up, so a CCT result is never evidence that austenitization completed.
What to do — Restate the cycle with the peak at or below 1000 °C and check the material summary the agent echoes back. Then read Known limits before treating a number as an answer; several grades and temperature ranges have recorded, quantified deviations. Remember that a numerical cooling rate is not a quench-medium model, and that predicted hardness is a bulk mixture value, not the hardness of one phase. See How we validate.
The run failed#
What it means — When a turn fails and the agent produced no text of its own, the conversation shows a line beginning "Operation failed:" followed by the public reason. Parameter problems are reported literally — for example "voltage must be > 0", or a chemistry whose elements sum past 100% rejected with a message telling you to adjust the values or omit Fe so it can be auto-balanced. An RSW solve that exceeds its 900-second budget is recorded as a failed run reporting "Simulation timed out".
What to do — Read the quoted reason; it names the field to fix. For a timeout, cut the number of steps the solver has to take — shorten the simulated total time, or use a coarser time step — and resubmit. A failed run is still recorded as a run, so the version number it reserved stays used. See Parameter blocks.
I closed the tab during a long run#
What it means — The simulation keeps going on the server after the browser disconnects, and its artifacts are still written to your run history. When you return to the session the chat reconnects to the running work and shows "Resuming simulation from background..." while it catches up. Replay of a finished turn is retained for about ten minutes; after that the reconnect endpoint reports that there is no active task for the session.
What to do — Reopen the same session and wait for the banner to clear. If the reconnect window has passed, look for the run in the simulation run history instead of the chat transcript — the stored plots and files are the durable record, not the conversation. See Sessions, runs and artifacts.
It says the operation could not be completed, with no reason#
What it means — "The operation could not be completed. The issue was recorded for investigation." is what an internal fault looks like from the outside. Phases does not show operator diagnostics in the conversation, and the agent is explicitly forbidden from inventing a plausible-sounding reason such as an interface or schema limitation in their place. The failure has been recorded.
What to do — Retry once; transient faults often clear. If it repeats on the same request, change one variable at a time — a different grade, a shorter cycle, a different simulator — to establish whether the problem follows the material or the setup, and report the session and what you typed. If a capability is disabled for your workspace you will get a different, explicit message naming it, and a workspace admin can re-enable it. See Workspaces and roles.
A simulator I expected is missing, or refuses to run#
What it means — Simulators can be turned off per workspace, in which case the tab disappears and any in-chat card for it is replaced by a notice saying it is disabled and to ask your admin. Separately, a workspace viewer cannot execute anything: simulation tools answer "This workspace role cannot run simulations. Ask a workspace admin for member access." Spot Weld Tester is not a configuration problem — it is unfinished scaffolding, shown with a "Soon" label and not selectable.
What to do — Ask a workspace admin to enable the simulator or to raise your role to member. For time-temperature-transformation diagrams specifically, there is nothing to enable: TTT is not implemented and returns "TTT transformation diagrams are not implemented yet." Only CCT runs. See CCT and TTT and Workspaces and roles.
If a term in a message is unfamiliar, the Glossary defines the product's vocabulary. And the standing note under the composer applies: "Phases can make mistakes. Check important info."