The original address: https://support.unity3d.com/hc/en-us/articles/206126976-What-is-CS1525-
symptoms
You see the following error in the Console window:

Error CS1525: Unexpected symbol ‘__, expecting’.

why
This error is raised when an invalid character is encountered in an expression. For example, the if statement in the following example does not allow the symbol “a” to follow the if statement.

The error message for this example is as follows:

Error CS1525: Unexpected Symbol ‘a’, expecting ‘(‘

The solution
Make sure the correct symbol appears in the expression. In this case, we need to add a “(” symbol to the right of the if statement, because the missing left parenthesis makes” a “an invalid symbol.

For more information
https://msdn.microsoft.com/en-us/library/3hdyz4dw(v=vs.90).aspx