Help me understand and fix this error.
ERROR MESSAGE:
```
[[ERROR]]
```
WHAT I WAS DOING: [[CONTEXT]]
STACK / LANGUAGE: [[STACK]]
RELEVANT CODE (if any):
```
[[CODE]]
```
Give me:
1. What the error actually means in plain English
2. The most likely cause here
3. The exact fix to try first
4. 1–2 other things to check if that doesn't work
5. How to avoid it next time