The most challenging part of RPA development isn’t when the flow stops—it’s when the flow finishes successfully, but the data is wrong. This is what we call a Silent Failure.
Perhaps the bot clicked the wrong button, a key command is missing, or your Excel file is full of "10+5" instead of "15." To fix these, you need to stop guessing and start investigating using a systematic diagnostic framework.
The Diagnostic Framework: Reverse Engineering
When the output doesn't match your expectations, follow this workflow:
Define the Gap: What exactly is wrong? (e.g., "The price column is empty" or "The loop only ran once").
Form a Hypothesis: Where could the logic break? (e.g., "Maybe the selector for the price is wrong" or "Maybe the 'If' condition is always false").
Collect Evidence: Use debugging tools to see what the bot "sees" during execution.
Your Diagnostic Toolkit: How to "See" the Logic
To find the root cause, you need to peek inside the bot's brain using these three essential tools:
Tool A: Instruction Logs (The Map)
The execution log isn't just for errors. It tells you exactly which instructions were skipped and which were executed.
Usage: If you expected 10 items but only see 1 "Success" log for the extraction step, you know the issue is within your Loop settings.
Tool B: Print to Log (The Probe)
Sometimes you need to know the value of a variable at a specific moment.
Action: Insert a Print to Log command before or after a critical step.
Usage: If your 'If' condition depends on a variable
Status, print that variable to the log. You might find it’s "Pending " (with a space) instead of "Pending", causing the match to fail.
Tool C: Breakpoints (The Microscope)
A breakpoint pauses the bot right before a specific instruction, allowing you to inspect the "live" state of all variables.
Action: Right-click the command to Add Breakpoint.
Usage: Perfect for complex loops. Pause the bot, check the variables, and step through the logic one by one to see where it deviates.
Common "Hidden" Root Causes
Even without a red error box, these logic bugs are frequent culprits:
Cause 1: Data Misinterpretation (Operators vs. Text)
The Case: You set a calculation to
10 + 5, but the output is the text string"10 + 5"instead of15.The Reason: The
+sign was treated as a literal character because it was typed into a text field.The Fix: Always use the Operator dropdown in the instruction panel to select
+,-, or*. This ensures the software recognizes it as a mathematical operation.
Cause 2: Logic Branching Errors
The Case: The bot consistently skips a specific task it was supposed to do.
The Analysis: Your If (Condition) might be using the wrong logic (e.g., using "Greater than" instead of "Greater than or equal to").
The Fix: Use Print to Log to see the actual values being compared right before the 'If' block.
Best Practices: "Debug as You Build"
Don't wait until the end to test.
Proactive Logging: Get into the habit of adding Print to Log at key logic junctions during development.
The Debug Flow: Result is wrong → Check logs to narrow the area → Set Breakpoints to inspect variables → Fix the logic.