I am quite new with Limesurvey. I have installed the software on a Linux server, and it mostly works. But I cannot perform site administration. I have an "admin" user, and can login with this, but this user has no special privileges. I have followed the instructions at wiki.contribs.org/limesurvey , and I think my problem may be due to the fact that limesurvey-users are authorized based on their known user names and passwords on the server.

Seems there are an issue on smeserver-limesurvey , not in LimeSurvey.

I think you are right. Is there anything I can do now, in order to give myself or another user superadmin-privileges? Right now, the users table has this content:
mysql> select * from users;
| uid | users_name | password | full_name | parent_id | lang | email | htmleditormode | templateeditormode | questionselectormode | one_time_pw | dateformat | created | modified |

| 1 | holck | 2f2038d757c5ba69e3e4d4db9c3e24186a8cf92b3b7fdbb1b341b3debb462173 | Jesper Holck | 1 | en | jesper.holck@ibsgaarden.dk | default | default | default | NULL | 1 | 2017-01-04 14:32:36 | 2017-01-04 19:32:46 |
| 2 | admin | a42cdeb3fd8db3c32392c65b8e845c03b12a5c6c827c7ddc3f0230a0ce025f8e | autouser | 1 | en | autouser@test.test | default | default | default | NULL | 1 | 2017-01-06 12:03:47 | NULL |

2 rows in set (0.00 sec)

I believed I found a way to give an existing user superadmin-rights, using MySQL:
mysql> insert into permissions (entity, entity_id, uid, permission, read_p) values ('global', 0, 1, 'superadmin', 1);
In this example, I update the permissions for the user with uid = 1 to include the superadmin-permission.