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Common Errors and Warnings

This guide explains common error messages and how to resolve them.

Feature Spec Reference

Module 3.7 — Circular Dependency Detection
Various validation modules

Errors (Block Action)

“Circular Dependency Detected”

  • Cause: You tried to create a dependency that would create a loop (A→B→C→A)
  • Solution: Remove or change one of the dependencies to break the loop
  • Example: Task A depends on B, B depends on C, you try to make C depend on A—forbidden

”Start Date Cannot Be Before Project Start”

  • Cause: Task start date is earlier than project start date
  • Solution: Adjust task start date to be on or after project start date

”Target Completion Must Be After Start Date”

  • Cause: In Create Project, target completion is before or same as start date
  • Solution: Set target completion to a date after start date

”Task Name Is Required”

  • Cause: You tried to create a task without entering a name
  • Solution: Enter a task name (1–200 characters)

“Select at Least One Working Day”

  • Cause: Work Week has no days checked
  • Solution: Check at least one day (Mon–Fri recommended)

“Duration Must Be Greater Than 0”

  • Cause: Task duration was set to a negative or zero value (except milestones, which have duration 0)
  • Solution: Enter a positive duration (e.g., 1, 2.5, 10)

Warnings (Non-Blocking)

“Task Has No Predecessors But Is Not ASAP”

  • Cause: Task with constraint (e.g., FNLT) has no predecessor
  • Meaning: Task may not schedule as expected
  • Action: Consider changing to ASAP or adding a predecessor

”Over-Constrained Task”

  • Cause: Task has conflicting constraints or dependencies that can’t be satisfied
  • Meaning: CPM engine had to override one constraint to calculate a valid schedule
  • Action: Review constraints and dependencies; remove one constraint if possible

”Circular Constraint Warning”

  • Cause: Constraint dates create an impossible situation
  • Example: Start No Earlier Than Jan 15 + Finish No Earlier Than Jan 10 = impossible
  • Action: Adjust constraint dates to be compatible

”Resource Over-Allocated”

  • Cause: Resource assigned to multiple overlapping tasks at >100% allocation
  • Meaning: Resource can’t be in two places at once
  • Action: Shift one task later, add another resource, or reduce allocation %

“Dependency Lag Exceeds Task Duration”

  • Cause: Lag value is larger than the predecessor task duration
  • Example: 5-day task with 10-day lag
  • Meaning: Unusual but not always wrong (intentional delay)
  • Action: Verify this is intentional; consider reducing lag

Validation Rules


Next Steps