[Error] expected unqualified-id before 'new'

This error message usually occurs when the compiler encounters the keyword 'new' in a place where it doesn't expect it. Some possible causes of this error are:

1. Missing semicolon: If you have missed a semicolon at the end of a statement, the compiler may interpret the next line as a continuation of the same statement and throw this error when it sees the 'new' keyword.

2. Incorrect syntax: If you have used the 'new' keyword incorrectly, such as trying to use it with a non-pointer type or using it without assigning the resulting pointer to a variable, the compiler will throw this error.

3. Name conflict: If you have defined a variable or function with the name 'new', the compiler may get confused when it sees the 'new' keyword and throw this error.

To fix this error, check your code for missing semicolons, incorrect syntax, and name conflicts. Also, make sure that you are using the 'new' keyword correctly and in the context where it is expected.