Error codes

When something goes wrong, Microbe Studio reports a stable code alongside the message — DETECT_REGION_TIMEOUT, MAX_NODE_EXECUTIONS_EXCEEDED, FLOW_PACKAGE_SIGNATURE_INVALID. The message is translated into your language; the code never changes, which makes it the thing to search for and the thing to quote in a bug report.

This page is organised by when you hit it, because that is how you look one up.

Retryable vs final

Some errors are marked retryable below. That means the runtime itself may try the operation again — for example a detection re-polls until its timeout. A final error stops there and needs you to change something.

This is separate from a node's own retry policy, and separate again from status versus route — a detection that finds nothing is not automatically an error at all. See Execution Model first if a "failure" surprised you.

While you are building a flow

These come from validation and from the editor. All are final: nothing retries an authoring mistake.

Graph and wiring

Code	What it means	What to do
FLOW_VALIDATION_ERROR	Validate found blocking problems	Step through them with ◀ Previous error / Next error ▶
TRANSITION_NOT_FOUND	A node returned a route with no edge wired	Add or fix an edge for the route it emitted — most often an unwired Failure port
EDGE_PORT_INVALID	An edge starts from a port that node does not have	Reconnect from a valid source port
NODE_TYPE_UNSUPPORTED	The flow carries a node type this build does not know	Remove it, or update the node — see Legacy Nodes
STALE_STATE	Your edit was rejected because the flow changed while you were editing	Nothing was lost. Redo the edit

Variables and expressions

Code	What it means	What to do
VARIABLE_NOT_DECLARED	An expression uses a name nothing declares	Declare it in Flow Inputs… or create it with a Variable node. Using a name is not declaring it
VARIABLE_TYPE_INVALID	A declared variable's type is not one the schema accepts	Fix the declared type
VARIABLE_SHADOWS_GLOBAL	A flow variable reuses a reserved global name	Rename the flow variable
TYPE_MISMATCH	A default or initial value violates the variable's declared type	Usually an OCR target declared number instead of number?. Declare OCR-bound variables nullable — a failed read writes empty, never a fabricated 0
EXPRESSION_SYNTAX_ERROR	The expression does not parse	Fix the syntax
EXPRESSION_NOT_BOOLEAN	A condition evaluated to something that is not true/false	Conditions must be boolean — compare, do not just reference
EXPRESSION_EVALUATION_FAILED	The expression parsed but blew up at run time	Check for missing values and division by zero

Loops

Code	What it means	What to do
LOOP_START_MISSING / LOOP_END_MISSING	A loop region is missing one of its markers	Every Loop has a paired Loop End the editor manages — do not delete one alone
LOOP_BODY_NOT_CLOSED	The body never reaches its Loop End	Wire the body through to the Loop End
LOOP_PAIR_AMBIGUOUS	Which Loop End belongs to which Loop cannot be decided	Simplify the nesting
LOOP_REGION_INVALID	The region shape is not a valid loop	Re-create the loop rather than repairing it by hand
LOOP_MODE_INVALID	The loop mode is not one of the accepted values	Pick a valid mode
LOOP_CONDITION_MISSING	A condition-driven loop has no condition	Supply one, or switch to a fixed count
LOOP_CONTROL_OUTSIDE_LOOP	Break or Continue sits outside any loop	Move it inside the loop region it is meant to control
MAX_ITERATIONS_INVALID	The iteration cap is not a usable number	Set a positive integer

Sub flows

Code	What it means	What to do
SUBFLOW_NOT_FOUND	A Sub Flow node points at a flow that no longer exists	Re-point it, or import the missing flow. Shows as missing in the dependency viewer
SUBFLOW_INVALID	The referenced child is not usable as a sub flow	Open the child and validate it
FLOW_CIRCULAR_DEPENDENCY / SUBFLOW_RECURSION_DETECTED	A flow calls itself, directly or through a chain	Remove the reference that closes the loop — the message names the chain
SUBFLOW_DEPTH_EXCEEDED	Nesting is deeper than allowed	Flatten it. Two or three levels covers almost everything — see Sub Flows
SUBFLOW_VARIABLE_CONFLICT	A child input collides with a name already in scope	Rename the input

Monitor scopes

Code	What it means	What to do
OBSERVER_FORBIDDEN_NODE	A node type that cannot live inside a watched zone is inside one	Move it out — see Monitor Scope
OBSERVER_NESTED_MONITOR	A monitor scope is inside another monitor scope	Monitors do not nest. Use one zone
OBSERVER_SPEC_INVALID	The scope's configuration is not valid	Re-create the scope
SCOPE_PAIR_AMBIGUOUS / SCOPE_REGION_INVALID	The zone's geometry cannot be resolved	Delete and re-cover the selection

Regions, points and templates

Code	What it means	What to do
RECT_TOO_SMALL	The drawn rectangle is below the usable minimum	Draw a bigger region
RECT_X_OVERFLOW / RECT_Y_OVERFLOW	The rectangle runs off the screen	Redraw inside the frame
POINT_INVALID / POINT_OUT_OF_BOUNDS	A coordinate is unusable or off-screen	Re-pick it on Live Preview
TEMPLATE_NOT_FOUND	A node references a template asset that is gone	Re-capture it, or re-import the flow package
TEMPLATE_QUALITY_TOO_LOW	The captured crop is too small or too plain to match reliably	Recapture a larger, more distinctive template
TEMPLATE_CHECKSUM_MISMATCH	The stored template file does not match its record	Recapture or repair the asset
TEMPLATE_CAPTURE_FAILED	The capture itself failed	Check the attached instance, then retry

While a flow runs

Guardrails — the run stopped on purpose

These are the runtime protecting you. All final.

Code	What it means	What to do
MAX_NODE_EXECUTIONS_EXCEEDED	The run executed more nodes than the flow allows	Loops multiply: 200 iterations over 12 nodes is ~2400 executions. Raise Max node executions…, or look for an unintended cycle
MAX_RUNTIME_DURATION_EXCEEDED	The run ran longer than its time cap	Split the workload, or raise the cap
MAX_CONSECUTIVE_FAILURES_EXCEEDED	Too many failures in a row with nothing succeeding between	Detection "not founds" do not cause this. Look for an action node failing repeatedly

Detection

Code	Retryable	What it means	What to do
DETECT_IMAGE_NOT_FOUND	yes	The template was not matched	Adjust the template, threshold, search region or timeout. Run Test Node and read the real confidence before touching the threshold
DETECT_AMBIGUOUS	yes	Several candidates matched and none wins	Review the candidates or tune the threshold
DETECT_REGION_TIMEOUT	yes	A Check Region rule never became true in time	Raise timeoutMs, adjust the rule, or verify what is actually in the region
DETECTION_ENGINE_FAILED	—	The matcher itself failed	Check the attached instance and the template asset

OCR

Code	Retryable	What it means	What to do
FEATURE_OCR_UNAVAILABLE	—	OCR is not installed or not enabled	Install and enable OCR (Tesseract) before running Read Text nodes. Also check the flow's ocrEnabled gate — this is the commonest cause of "Read Text does nothing"
OCR_LANGUAGE_MISSING	—	The requested language pack is not installed	Install that Tesseract language pack, or pick an available language
OCR_FAILED	—	The OCR call failed	Check the OCR executable path in Settings
OCR_EXTRACT_NO_MATCH	yes	OCR read text, but the extraction pattern matched nothing in it	Compare your pattern against the raw read in Text read result. If the raw text is wrong, the region or content type is wrong — not the pattern
OCR_REGEX_INVALID	—	The custom pattern does not compile	Fix the regex
OCR_CONFIG_INVALID	—	The OCR settings are not a usable combination	Re-check language and content type

Actions and input

Code	Retryable	What it means	What to do
COORDINATE_SOURCE_UNAVAILABLE	yes	A Click points at a Find Image node that has not produced a match on this path	Run the Find Image first, or verify it matched before the click. This is what a copy-pasted Click usually hits
COORDINATE_PROFILE_INVALID	—	The coordinate profile is unusable	Re-pick the target
INPUT_FAILED	—	The emulator rejected the input	Check the instance is reachable and focused
INPUT_COMMAND_TIMEOUT	—	The input command did not complete in time	Check emulator load
TEXT_EMPTY	—	Input Text has nothing to type	Supply text, or a variable that is not empty
TEXT_UNSUPPORTED_CHARACTER	—	A character cannot be sent to the emulator	Remove or transliterate it
TEXT_NOT_FOUND / TEXT_MATCH_INVALID	—	A text match target or rule is unusable	Fix the match configuration
TEXT_MODE_UNSUPPORTED / TEXT_CLEAR_UNSUPPORTED	—	The requested typing or clearing mode is not available	Pick a supported mode
SWIPE_INVALID	—	The Swipe geometry is unusable	Redraw start and end
KEY_UNSUPPORTED	—	That key is not sendable	Pick another key
WAIT_INVALID	—	The wait duration is not usable	Set a positive duration

Captcha

Code	Retryable	What it means	What to do
FEATURE_CAPTCHA_UNAVAILABLE	—	The captcha solver is not available in this build	Check the flow's captcha feature gate
CAPTCHA_UNSOLVED	yes	The challenge was not solved within the attempts allowed	Raise Max attempts, check the challenge region, or wire the unsolved output to a refresh-and-retry path

Emulator and instance

Code	What it means	What to do
INSTANCE_NOT_ATTACHED	The action needs an attached preview instance and there is none	Attach one in Live Preview
INSTANCE_NOT_FOUND	The referenced instance is gone	Re-scan with Add Instance
INSTANCE_OFFLINE	The instance is not reachable	Start the emulator
INSTANCE_IDENTITY_AMBIGUOUS	Two instances cannot be told apart	Check the MuMu instance list
INSTANCE_LAUNCH_FAILED / INSTANCE_SHUTDOWN_FAILED	Start or stop did not take	Check MuMu directly, then retry
INSTANCE_ATTACH_FAILED / INSTANCE_DETACH_FAILED	Attaching the preview failed	Re-open Live Preview
INSTANCE_REGISTRY_PARSE_FAILED / INSTANCE_PLAYER_STATE_UNKNOWN	MuMu's own state could not be read	Restart MuMu
MUMU_CLI_UNAVAILABLE	mumu-cli.exe was not found	Set the path in Settings — see Troubleshoot MuMu CLI
MUMU_CLI_INFO_FAILED / MUMU_CLI_ADB_FAILED / MUMU_CLI_CONTROL_FAILED	A MuMu CLI call failed	Check the CLI path and that MuMu is running
MUMU_DISCONNECTED	The connection to MuMu dropped mid-run	Re-attach; check whether the emulator restarted
SCREEN_CAPTURE_FAILED / FRAME_UNAVAILABLE	A frame could not be captured	Check the instance is running and not minimised in a way that blocks capture

While you are operating

Code	What it means	What to do
QUEUE_FLOW_NOT_FOUND	A queue entry points at a flow that is gone	Remove the entry or re-import the flow
QUEUE_RESOLUTION_MISMATCH	The flow/instance resolution pair differs from the one you confirmed	Your earlier "Add anyway" covered the pair you actually saw. Confirm again — see Flow Queue
SCHEDULE_NOT_FOUND	The schedule is gone	Re-create it
SCHEDULE_INVALID	The schedule's timing is not usable	Check recurrence, time and timezone
SCHEDULE_IMPORT_INVALID	The file is not a valid .muscheduler export	Re-export it
SCHEDULE_IMPORT_FLOW_MISSING	Flows in the file do not exist on this machine	Choose a replacement for each before importing
DEPLOYMENT_NOT_FOUND / DEPLOYMENT_START_FAILED / DEPLOYMENT_STOP_FAILED	A deployment action did not complete	Check the target instance

Packages, licence and account

Code	What it means	What to do
FLOW_PACKAGE_INVALID	The package file is not readable as a package	Get a fresh copy
FLOW_PACKAGE_SIGNATURE_INVALID	The signature check failed — modified after export, or not from a trusted publisher	Do not import it. Get a new copy from the original publisher
FLOW_PACKAGE_CHECKSUM_MISMATCH	The contents do not match the manifest	The file is damaged or truncated. Re-download
FLOW_PACKAGE_DEPENDENCY_MISSING	A sub flow the package depends on is absent	Import the complete package, not one flow from it
FLOW_PACKAGE_KEY_REQUIRED / FLOW_PACKAGE_KEY_INVALID	A protected package needs a key you do not have or the key is wrong	See Flow Intellectual Property
FLOW_PACKAGE_IMPORT_FAILED / FLOW_PACKAGE_EXPORT_FAILED	The transfer failed for another reason	Check disk space and permissions
FLOW_IMPORT_DUPLICATE_ID	A flow with that id already exists	Overwrite deliberately, or rename
FLOW_OWNERSHIP_FORBIDDEN	Your account may not use this flow	Check who the flow belongs to
FLOW_LICENSE_EXPIRED	A time-limited Flow License has run out	Renew it — renewal adds to the remaining time
FLOW_AUTHORIZE_OFFLINE	A protected flow needs an online check and the server was unreachable	Reconnect and retry
CAPABILITY_NOT_LICENSED	Your licence does not include a capability the flow uses	Check the capability list on your account
AUTH_REQUIRED	You are not signed in	Sign in
AUTH_SERVER_UNAVAILABLE	The portal could not be reached	Check your connection
FLOW_IN_USE / FLOW_EDIT_LOCKED	The flow is running or open elsewhere	Stop the run, or close the other editor
ASSET_IN_USE	The asset is referenced by a flow	Remove the references first

Advanced Captcha (AI)

Code	What it means	What to do
AI_MODEL_NOT_INSTALLED	No model archive has been imported	Download and import it through Settings → Advanced Captcha
AI_ARCHIVE_INVALID	The archive is not readable	Re-download it
AI_ARCHIVE_UNTRUSTED	The archive is not signed by a trusted source	Do not import it
AI_ARCHIVE_INCOMPATIBLE	The archive does not match this build	Get the archive for your version
AI_INSTALL_FAILED	Importing failed	Check disk space
AI_RUNTIME_UNAVAILABLE	The local AI runtime is not available	Re-run the install
AI_INFERENCE_FAILED	The model ran but failed on this challenge	Without Advanced Captcha the node still runs on the offline solver — check whether the offline path handles it

Retired node families

PARALLEL_BRANCH_INVALID, PARALLEL_START_MISSING, PARALLEL_END_MISSING, PARALLEL_PAIR_AMBIGUOUS, PARALLEL_REGION_INVALID belong to the retired Parallel node. If you see one, the flow still carries that node. It never made anything concurrent — see Legacy Nodes and replace it with a Monitor Scope.

Internal codes

These come from layers below the flow you author — schema migration, the editor's own persistence, and the process boundary between the UI and the runtime. You will rarely see one, and when you do the fix is usually "restart the app" or "report it with the code".

SCHEMA_INVALID · SCHEMA_VERSION_UNSUPPORTED · SCHEMA_MIGRATION_MISSING · SCHEMA_MIGRATION_AMBIGUOUS · SCHEMA_MIGRATION_FAILED · SCHEMA_MIGRATION_INVALID_OUTPUT · IPC_PROTOCOL_UNSUPPORTED · IPC_COMMAND_UNKNOWN · IPC_PAYLOAD_INVALID · IPC_TIMEOUT · PERSISTENCE_FAILED · AUTOSAVE_FAILED · EVENT_LOG_CORRUPT · SNAPSHOT_INVALID · REPLAY_MISMATCH · STATE_INVALID · UI_STATE_INVALID · PROJECT_NOT_FOUND · PROJECT_INVALID · PARAM_INVALID · OUTPUT_MAPPING_INVALID · MEMORY_SCOPE_INVALID · MONITOR_SPEC_INVALID · ASSIGNMENTS_EMPTY · SHARE_FORBIDDEN · STOP_REQUESTED · SCALE_INVALID · USER_ABORTED · REGION_NOT_FOUND · DETECTION_ENGINE_FAILED

Quoting an error

Copy the code, not the translated sentence. Copy Result in the Properties panel puts a node's whole test result on the clipboard, which is the most useful thing you can attach to a report.

Related pages

• Retry and Failures — choosing between a longer timeout, a failure edge and a retry policy
• Execution Model — why a "not found" is not a failure
• Testing and Validation — catching these before a run
• FAQ — the errors people hit most, with the reasoning