Common causes
1. Typo
rsi = ta.rsi(close, 14)
plot(xRsi) // ⚠ typo
Rename or alias the reference.
2. Variable used before declaration
plot(rsi) // ⚠ not declared yet
rsi = ta.rsi(close, 14)
Move the declaration above its first use. ChartScript is single-pass — forward references to top-level identifiers are not allowed.
3. Namespaced function missing the prefix
m = sma(close, 20) // v1-v4 alias — still works
m = sma(close, 20) // but a UDT or variable named `sma` shadows it
If a local variable happens to share the name of a bare-alias built-in, the compiler will try to use the local. Rename the local or call the built-in through its namespace (ta.sma).
4. Reaching into a library whose import is missing
plot(sig.smooth(close, 5)) // ⚠ 'sig' is undeclared
// forgot the `import` line
Add:
import 1000000072/Signal/1 as sig
5. Enum member mistyped
enum Trend
up
down
flat
plot(0, color = Trend.flst) // ⚠ 'flst' is not a Trend member