SAP Note 28827 - 3.0A Project Creation Blocked by TCJ01

Symptom:

Among the parameters that the user must maintain for project editing is
the length of the structure indicator.
As long as there is no project, you can enter any length in the interval
1-5 in table TCJ01.
Once there is a project you can no longer change the indicator.
In previous releases the system did not check whether a project already
existed.

Cause and prerequisites

Error in the coding

Solution
See below