Solved installation error

yes you can remove kunena completely, no prob!

Yes, I think I found the problem. Seems to be a wrong server setting. Go in backend to "System -> System Information -> tab PHP Information".
Press Strg + F and search the entry memory_limit
In your PHP Setting shows
memory_limit = -1
but it should be
64 Mb or even 128 Mb (minimum is 32Mb I think)

yes you can remove kunena completely, no prob!

Unfortunately that also does not work. Please remove the Kunena tables again manually. Then check in the server setting the memory limit please.

Dear Rich,

I did as you wrote: I enabled memory limit to more than 500 MB. see 2019.psychoanalyse-muenchen.de/phpinfo.php
I deleted allt ables in databse and deinstalled firstly kunena completely but still same error as above.

I tried now version 5.1.6 but same error message

maybe in .htaccess something is missing:

#
# @package Joomla
# @copyright Copyright (C) 2005 - 2019 Open Source Matters. All rights reserved.
# @license GNU General Public License version 2 or later; see LICENSE.txt
##

##
# READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE!
#
# The line 'Options +FollowSymLinks' may cause problems with some server configurations.
# It is required for the use of mod_rewrite, but it may have already been set by your
# server administrator in a way that disallows changing it in this .htaccess file.
# If using it causes your site to produce an error, comment it out (add # to the
# beginning of the line), reload your site in your browser and test your sef urls. If
# they work, then it has been set by your server administrator and you do not need to
# set it here.
##

## No directory listings
<IfModule autoindex>
IndexIgnore *
</IfModule>

## Suppress mime type detection in browsers for unknown types
<IfModule mod_headers.c>
Header always set X-Content-Type-Options "nosniff"
</IfModule>

## Can be commented out if causes errors, see notes above.
Options +FollowSymlinks
Options -Indexes

## Mod_rewrite in use.

RewriteEngine On
RewriteBase /
RewriteRule ^([a-z]+)\.html$ /index.php?$1 [R,L]

## Begin - Rewrite rules to block out some common exploits.
# If you experience problems on your site then comment out the operations listed
# below by adding a # to the beginning of the line.
# This attempts to block the most common type of exploit `attempts` on Joomla!
#
# Block any script trying to base64_encode data within the URL.
RewriteCond %{QUERY_STRING} base64_encode[^(]*\([^)]*\) [OR]
# Block any script that includes a <script> tag in URL.
RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
# Block any script trying to set a PHP GLOBALS variable via URL.
RewriteCond %{QUERY_STRING} GLOBALS(\[|\%[0-9A-Z]{0,2}) [OR]
# Block any script trying to modify a _REQUEST variable via URL.
RewriteCond %{QUERY_STRING} _REQUEST(\[|\%[0-9A-Z]{0,2})
# Return 403 Forbidden header and show the content of the root home page
RewriteRule .* index.php [F]
#
## End - Rewrite rules to block out some common exploits.

## Begin - Custom redirects
#
# If you need to redirect some pages, or set a canonical non-www to
# www redirect (or vice versa), place that code here. Ensure those
# redirects use the correct RewriteRule syntax and the [R=301,L] flags.
#
## End - Custom redirects

##
# Uncomment the following line if your webserver's URL
# is not directly related to physical file paths.
# Update Your Joomla! Directory (just / for root).
##

# RewriteBase /

## Begin - Joomla! core SEF Section.
#
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
#
# If the requested path and file is not /index.php and the request
# has not already been internally rewritten to the index.php script
RewriteCond %{REQUEST_URI} !^/index\.php
# and the requested path and file doesn't directly match a physical file
RewriteCond %{REQUEST_FILENAME} !-f
# and the requested path and file doesn't directly match a physical folder
RewriteCond %{REQUEST_FILENAME} !-d
# internally rewrite the request to the index.php script
RewriteRule .* index.php [L]
#
## End - Joomla! core SEF Section.

forgive me for writing you again, I just wanted to mention that yesterday when I checked the installation I saw that kunena was succesfully installed but today it was gone again.....why so ?

forgive me for writing you again, I just wanted to mention that yesterday when I checked the installation I saw that kunena was succesfully installed but today it was gone again.....why so ?

Before I had written yesterday it was my last login yesterday. Now I are again in the backend, but do nothing currently, because I see, also you are in the backend and I don't know what you are try.

I wasnt doing anything, I just saw that yesterday the dashboard of kunena was visible so i thought you were succesful but 1 day later when I opened it again , the error message came again....my question was to you why it worked and 1 day later it is gone again....

Maybe I had before logged out tried to install Kunena 5.1.6.1 instead of 5.1.6 (it is the last version which is possible to install). Now is the dashboard back again. But there are many errors and the debug shows also missing database tables.
I've now installed a clean Kunena 5.1.10.1 on my test page, and the Kunena tables exported and the prefixes adjusted for your page.
Please check your E-mail, I've send it to you.
Delete all Kunena tables from your page and import this tables. Then try to install Kunena 5.1.10.1.

Fuck, it worked!!!, I did as you wrote: I deleted all tables, imported yr tables and then I installed latest kunena version. why the heck it worked now?