That sounds like something you need to set in your Host Server Control panel (such as cPanel). Usually you will assign a user with privileges to the FTP. I would suggest you login to your control interface and see which user is assigned to the FTP account you are using, then check the users privileges/properties and set it accordingly.

To add to achillis post, does the database user have all privileges as it decides if you can upload and edit it's data(posts and everything else too)

More info:
Blog as a user has ' - - grant all privileges on . - - ' in the database.

I can connect to the server, move around, read and look at all default pics and delete posts and users in the blog, that is ok.
Altering setup, a new post or editing a post gives a errormsg when I try to save it.
I try alter the rights like this: sudo chmod 777 -R html.
Still I get errormsg like this:
Fatal error: Uncaught Error: Call to undefined function xml_parser_create() in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php:145 Stack trace: #0 /var/www/html/inc/_core/_param.funcs.php(2494): XHTML_Validator->__construct('posting', '1', '0', '0', '0', 'UTF-8') #1 /var/www/html/inc/_core/_param.funcs.php(2229): check_html_sanity('This is the lon...', 'posting', Object(User), 'utf-8') #2 /var/www/html/inc/collections/model/_blog.class.php(795): param_check_html('blog_longdesc', 'Invalid long de...') #3 /var/www/html/inc/collections/coll_settings.ctrl.php(110): Blog->load_from_Request(Array) #4 /var/www/html/admin.php(224): require('/var/www/html/i...') #5 {main} thrown in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php on line 145

@la2yg wrote earlier:

More info:
Blog as a user has ' - - grant all privileges on . - - ' in the database.

I can connect to the server, move around, read and look at all default pics and delete posts and users in the blog, that is ok.
Altering setup, a new post or editing a post gives a errormsg when I try to save it.
I try alter the rights like this: sudo chmod 777 -R html.
Still I get errormsg like this:
Fatal error: Uncaught Error: Call to undefined function xml_parser_create() in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php:145 Stack trace: #0 /var/www/html/inc/_core/_param.funcs.php(2494): XHTML_Validator->__construct('posting', '1', '0', '0', '0', 'UTF-8') #1 /var/www/html/inc/_core/_param.funcs.php(2229): check_html_sanity('This is the lon...', 'posting', Object(User), 'utf-8') #2 /var/www/html/inc/collections/model/_blog.class.php(795): param_check_html('blog_longdesc', 'Invalid long de...') #3 /var/www/html/inc/collections/coll_settings.ctrl.php(110): Blog->load_from_Request(Array) #4 /var/www/html/admin.php(224): require('/var/www/html/i...') #5 {main} thrown in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php on line 145

@la2yg are you hijacking @jogeta post here?

Check your php version. I suspect it is related to this http://forums.b2evolution.net/6-9-5-won-t-load-as-expected

I think the problem is related to my installing be2 in ubuntu. I'll do a new install of ubuntu 16.04 and do it right from the beginning (I belive).
Thanks for responding to my question.

By the way, I'll post a final about my new installation.

(jogeta and la2yg are the one and the same person, I'll tidy that up)

Before you do, please post your server PHP version here please.

Hi, 'php --version' gave this result:

PHP 7.0.18-0ubuntu0.16.04.1 (cli) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2017
Zend Technologies with Zend OPcache v7.0.18-0ubuntu0.16.04.1,
Copyright (c) 1999-2017, by Zend Technologies