When you build a report and want to add new variables, the formula list you see may be registered on the organisation rather than on the project. In that case you can only edit it if you have write permissions at organisation level. Without those permissions, new variables are not saved.
Create a separate formula list on the project
If you do not have permissions for the organisation's formula list, you can create a separate formula list that is saved directly on the project. The formulas you add there become available in your project in addition to the formulas from the organisation's formula list — the two lists are used together.
«SyntaxError» when I type an operator
The error message usually appears when nothing follows directly after the operator, for example when you have typed * without a number or variable after it. Complete the expression and the message disappears.
Read more about roles and access levels (project, department, organisation, group) in What roles are there in AIMZ, and what can each role do?