Invalid logical operator – Use of an invalid or unsupported logical operator.

The “Invalid Logical Operator” error occurs in Power Automate when an unsupported or incorrectly formatted logical operator is used in a condition or expression.

Error Message:
"Invalid logical operator – Use of an invalid or unsupported logical operator."

Logical operators are used to evaluate conditions, such as:

• Equality (== or eq)
• Inequality (!= or ne)
• Greater than (> or gt)
• Less than (< or lt)
• Logical AND (&& or and)
• Logical OR (|| or or)

If these operators are incorrectly formatted, misspelled, or used with incorrect data types, the flow will fail with this error.

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2. Common Causes of “Invalid Logical Operator” Error

Cause	Description	Incorrect Example	Correct Example
Wrong Syntax for Operators	Using == instead of eq in Power Automate expressions.	if(variables('Status') == 'Active')	if(equals(variables('Status'), 'Active'))
Using Unsupported Operators	Power Automate does not support some common programming operators like && and `		`.
Incorrect Data Type Comparisons	Comparing incompatible data types (e.g., number vs. text).	if(5 > 'Ten')	if(5 > int('10'))
Operator Placement Issue	Logical operators used incorrectly in expressions.	if(and(Status eq 'Active', Age gt 18))	if(and(equals(Status, 'Active'), greater(Age, 18)))

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3. Step-by-Step Troubleshooting Guide

Step 1: Identify the Invalid Operator in the Expression

1. Open Power Automate (https://flow.microsoft.com).
2. Go to My Flows and locate the flow that failed.
3. Click Run History and expand the failed action.
4. Look for error details that mention “invalid operator” or “syntax error.”

Example Error Message:

"The template language function 'if' was invoked with an incorrect operator '=='. Use 'equals()' instead."

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Step 2: Use Power Automate’s Supported Logical Operators

Power Automate does not support common programming symbols like ==, !=, &&, or ||. Instead, it requires expression functions such as equals(), and(), and or().

Solution: Convert standard operators to Power Automate expressions.

Example Fix:

Incorrect	Correct
Status == 'Active'	equals(Status, 'Active')
Status != 'Inactive'	not(equals(Status, 'Inactive'))
Age > 18	greater(Age, 18)
Age >= 18	greaterOrEquals(Age, 18)
Age < 30	less(Age, 30)
Age <= 30	lessOrEquals(Age, 30)
Status == 'Active' && Age > 18	and(equals(Status, 'Active'), greater(Age, 18))
`Status == ‘Active’

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Step 3: Verify Logical Operators in Condition Blocks

If the error occurs inside a Condition action, make sure the correct Power Automate syntax is used.

Solution: Update the logic to use supported operators.

Example Fix:

Incorrect (== used instead of equals()):

if(variables('Status') == 'Active')

Correct (equals() function used):

if(equals(variables('Status'), 'Active'))

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Step 4: Check for Incorrect Data Type Comparisons

Logical operators must be used with matching data types. Comparing text and numbers directly can cause an error.

Solution: Convert data types using int() or string().

Example Fix:

Incorrect (comparing number with text):

greater(5, 'Ten')

Correct (convert text to number using int()):

greater(5, int('10'))

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Step 5: Fix Incorrect Placement of Operators

Ensure logical operators are used within the correct expression structure.

Solution: Follow Power Automate’s function-based syntax for and() and or().

Example Fix:

Incorrect (wrong placement of eq and gt):

if(and(Status eq 'Active', Age gt 18))

Correct (use equals() and greater() inside and()):

if(and(equals(Status, 'Active'), greater(Age, 18)))

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Step 6: Test the Fixed Flow

After making corrections:

1. Click Save in Power Automate.
2. Select Test and run the flow manually.
3. If the error is resolved, verify the flow’s output.

If the error persists, return to Step 1 and check for additional syntax issues.

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4. Preventative Measures

✔ Use Power Automate’s “Expression Builder” to validate logical expressions before saving.
✔ Refer to Power Automate’s official documentation for supported operators.
✔ Avoid using programming-style logical symbols (==, !=, &&, ||) and use Power Automate’s expressions instead.
✔ Ensure data types match when using logical conditions.
✔ Test expressions inside a “Compose” action before using them in conditions.