Fatal error: Function name must be a string

[Sir Osis of Liver]

Your server is running php 5.3.29, you must upgrade at least to 5.4 if you want to run SMF 2.0.15.  upgrade.php should run (haven't tried it), but forum will not.  You may be able to upgrade php in your host control panel, if not ask your host to do it.  Php 5.3 went eol over 3 years ago, currently supported versions are 5.6, 7.0, 7.1, 7.2.  I'm using 5.6.32, works fine with all things SMF.  Let me know when it's upgraded, and I'll upgrade your forum.

[Aleksi "Lex" Kilpinen]

I could only upgrade to 1.1.21. Is there any way to add the custom questions during the new member registration, in this version?

You could continue updating by using the large upgrade package. Or did you try this already and hit a problem?

[serge06]

I PM'ed the server login to one of the admins, so hopefully he is looking into the issue.

[Aleksi "Lex" Kilpinen]

OK, let us know if you need further assistance, or if you feel this topic has served it's purpose you can mark the topic solved as well.