# How to interpret personalization errors?

### “Illegal char…”

**Meaning**: A character appeared where only a name, number, separator, or part of a string was expected.

**Typical Causes:**

* Using the string delimiter (`'`) or variable prefix (`$`) in the wrong place.
* Mixing double quotes where the language requires single quotes.
* Introducing a non-alphanumeric character while building an identifier or a number.

**Examples:**

👉 `{% if trigger_event.name == “John” %}` instead of `{% if trigger_event.name == 'John' %}` 

⇒ *The issue is the double quotes* `“”`*.*

👉`price $ 30` instead of `price == 30` 

⇒ `$` *on its own becomes an illegal char.*

### “Illegal token…”

**Meaning**: A symbol of this type is not allowed in this part of the code.

**Typical Causes**

* Forgetting a comma between arguments.
* Using the wrong operator.

**Examples:**

👉 `price => 3` instead of `price >= 3` 

⇒ *The correct operator is* `>=`.

👉 `{% set $product = lookup('products' '1') %}` instead of 

`{% set $product = lookup('products', '1') %}` 

⇒ *There should be a comma between the catalog name* `‘products’` *and the catalog id* `‘1’`.

### “Unbalanced parenthesis…”

**Meaning**: Closing a parenthesis incorrectly or without valid arguments.

**Example** :

👉`{% set $product = lookup('products', '1' %}` instead of

`{% set $product = lookup('products', '1') %}` 

⇒ *The second parenthesis after the catalog id* `‘1’` *is missing.*

### “Unbalanced sections…”

**Meaning:** The control block was not properly closed.

**Example:**

👉 `{% if age > 5 %}`` `**`CONTENT`** instead of `{% if age > 5 %}`` `**`CONTENT`**` ``{% endif %}` 

⇒ *The closing block* `{% endif %}` *is missing.*

### “Unbalanced string…” :

**Meaning**: A string was opened but not properly closed.

**Example**:

👉 `{% if name == 'XYZ %}` instead of `{% if name == 'XYZ' %}` 

⇒ *The closing quote* `‘` *is missing.*

### **“Illegal attribute/tag/event name …”**

**Meaning:** The name doesn’t match the expected format, scope, or permissions.

**Example:**

👉 `user..age` instead of `u.age` or `age` 

⇒ *The format of the attribute is incorrect.*

### **“A var name and then the equal operator was expected”**

**Meaning**: After `{% set`, there must be a `$variable` followed by `=`.

**Example:**

👉 `{% set = 3 %}` instead of `{% set $user_id = 3 %}` 

⇒ *The* `$variable` *is missing.*

### **“A var name and then the 'in' keyword was expected”**

**Meaning**: After `{% for`, there must be a variable followed by `in`.

**Example**:

👉 `{% for $item list %}` instead of `{% for $item in list %}` 

⇒ *The* `in` *is missing.*

### **“The body can't be empty”**

**Meaning**: The block associated with an `if`, `else if`, `else` or `for` is empty.

**Example:**

👉`{% if condition %}{% endif %}` instead of `{% if condition %}`**`CONTENT`**`{% endif %}` 

⇒ *There is no content between the display conditions (for dynamic content in SMS, push and In-App).*

### **“Illegal sign operator”**

**Meaning:**

`+` or `-` is used in front of a value that is not a number.

**Example:**

👉 `{% if -true > user_score %}` instead of `{% if -4 > user_score %}`

⇒ `true` *is not a number, and therefore* `-true` *is not valid.*

### **“Invalid filter”**

**Meaning**: The filter used to transform the argument is incorrect.

**Example:**

👉`{% if first_name|title(nullIfEmpty:true) != None %}` instead of 

`{% if first_name|trim(nullIfEmpty:true) != None %}` 

⇒ *The filter* `title(nullIfEmpty:true)` *is incorrect.*

### “Illegal end of string…”

**Meaning:** The string ends too early due to a closing parenthesis missing or placed incorrectly.

**Example:**

👉 `hello {{first_name` instead of `hello {{first_name}}` 

⇒ *The closing parenthesis is missing.*

### “Illegal decimal separator…”

**Meaning:** The symbol used to separate the whole part from the fractional part of a number is incorrect.

**Example:**

👉 `{% if age > 1..5 %}` instead of `{% if age > 1.5 %}` 

⇒ *The decimal is incorrect.*

### “Illegal unit char…”

**Meaning:** A character that isn’t allowed appeared inside a unit (the part that describes measurement like `kg`, `ms`, `cm`).

**Example:**

👉`{% if distance > 10km@ %}` instead of `{% if distance > 10km %}` 

⇒ *The unit is incorrect.*

### “Unable to parse this constant…”

**Meaning:** The system couldn’t read the constant because it’s malformed or contains invalid characters.

**Example:**

👉 `{% if subscription_date == 90days %}` instead of `{% if subscription_date == 90d %}` 

⇒ *The constant* `days` *is incorrect.*

### “Partial tag… is not allowed”

**Meaning**: A partial tag is a tag whose full set of values cannot be listed. If a tag is partial (like `b.custom_audiences`), you cannot use it where the system must enumerate or join all values.

**Example:**

👉 `{{ b.custom_audiences | join(", ") }}` 

⇒ *The system cannot return the complete list of audiences for an installation.*