I permanently disabled selinux and firewalld (and restart):

(base) [ivan@localhost ~]$ getenforce
Disabled
(base) [ivan@localhost ~]$ firewall-cmd --state
not running

Then I successfully installed the boinc:

sudo yum install boinc-client boinc-manager
sudo systemctl enable boinc-client.service
sudo reboot

When checking the service ability, I get the following output (the round label is green):

(base) [ivan@localhost ~]$ ps aux | grep boinc
boinc        863  0.0  0.0  26156 10264 ?        SNsl 16:22   0:00 /usr/bin/boinc
ivan        1994  0.0  0.0 216216   644 pts/1    S+   16:24   0:00 grep --color=auto boinc
(base) [ivan@localhost ~]$ systemctl status boinc-client.service
● boinc-client.service - Berkeley Open Infrastructure Network Computing Client
     Loaded: loaded (/usr/lib/systemd/system/boinc-client.service; enabled; vendor preset: disabled)
     Active: active (running) since Wed 2020-12-16 16:22:13 MSK; 2min 21s ago
       Docs: man:boinc(1)
   Main PID: 863 (boinc)
      Tasks: 2 (limit: 14178)
     Memory: 26.0M
        CPU: 643ms
     CGroup: /system.slice/boinc-client.service
             └─863 /usr/bin/boinc

Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---]    max disk usage: 68.33 GB
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---]    don't use GPU while active
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---]    suspend work if non-BOINC CPU load exceeds 25%
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---]    (to change preferences, visit a project web site or select Preferences in the Manager)
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---] Setting up project and slot directories
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---] Checking active tasks
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---] Setting up GUI RPC socket
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---] Checking presence of 0 project files
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 [---] This computer is not attached to any projects
Dec 16 16:22:16 localhost.localdomain boinc[863]: 16-Dec-2020 16:22:16 Initialization completed
(base) [ivan@localhost ~]$ pgrep -l boinc
863 boinc

But when I start the GUI utility, it's not active.

I was looking for methods to solve this problem, and some instructions suggest changing the permissions on the file /etc/boinc-client/gui_rpc_auth.cfg, but I don't have such a folder:

(base) [ivan@localhost ~]$ ls -l /etc |grep boinc
(base) [ivan@localhost ~]$

How to treat?

If you run top is the client running? If not you can start it with,

sudo systemctl start boinc-client

You say that when you start the gui “it’s not active”. What are the symptoms? what do you see? What error messages are presented?

Firstly, could you scan the whole drive for gui_rpc_auth.cfg, in some implementations it is in, for example, /var/lib/boinc[_client]. If you find it look at the contents, it should hold just the password with no eol etc.

If Boinc Manager comes up but is blank try going into >file>select computer and entering the computer name and the password you’ve (hopefully) just found or created. That should connect the manager to the client.

If you run top is the client running? If not you can start it with,

sudo systemctl start boinc-client

I tried this:

sudo systemctl stop boinc-client
sudo systemctl disable boinc-client
sudo reboot

And after reboot:

sudo systemctl enable boinc-client
sudo systemctl start boinc-client

I also tried changed word 'boinc-client' on 'boinc-client.service' in all command, but anyway Boinc- client doesn't work.

You say that when you start the gui “it’s not active”. What are the symptoms? what do you see? What error messages are presented?

No any masseges. only gray inactive GUI interface.

Firstly, could you scan the whole drive for gui_rpc_auth.cfg, in some implementations it is in, for example, /var/lib/boinc[_client]. If you find it look at the contents, it should hold just the password with no eol etc.

Yes, I found this file in /var/lib/boinc and gave full rights to it:

(base) [ivan@localhost boinc]$ ls -l
total 92
-rw-r--r--. 1 boinc boinc 52770 Dec 16 15:23 all_projects_list.xml
-rw-r--r--  1 boinc boinc  5928 Dec 17 07:56 client_state_prev.xml
-rw-r--r--  1 boinc boinc  5928 Dec 17 07:56 client_state.xml
-rw-r--r--  1 boinc boinc  3080 Dec 17 07:56 coproc_info.xml
-rw-r--r--  1 boinc boinc   112 Dec 17 07:53 daily_xfer_history.xml
-rwxrwxrwx. 1 boinc boinc    32 Dec 16 15:23 gui_rpc_auth.cfg
-rw-r--r--  1 boinc boinc     0 Dec 17 07:56 lockfile
drwxrwx--x. 2 boinc boinc  4096 Dec 16 15:23 notices
-rw-r--r--. 1 boinc boinc     0 Dec 16 15:23 stderrgpudetect.txt
-rw-r--r--. 1 boinc boinc   544 Dec 17 07:56 stdoutgpudetect.txt
-rw-r--r--. 1 boinc boinc  2605 Dec 17 07:57 time_stats_log

In file only 1 line:

nano gui_rpc_auth.cfg
3f0224b........7877m2

If Boinc Manager comes up but is blank try going into >file>select computer and entering the computer name and the password you’ve (hopefully) just found or created. That should connect the manager to the client.

I tried this. I discover hostname like this:
(base) [ivan@localhost boinc]$ sudo hostnamectl

[sudo] password for ivan: 
   Static hostname: localhost.localdomain
         Icon name: computer-desktop
           Chassis: desktop
        Machine ID: 3fcff07d60964f9ea82e973992a55989
           Boot ID: 7eee0bace5584b8ca5618ce7ab778696
  Operating System: Fedora 32 (KDE Plasma)
       CPE OS Name: cpe:/o:fedoraproject:fedora:32
            Kernel: Linux 5.9.13-100.fc32.x86_64
      Architecture: x86-64

But when I wrote localhost.localdomain in a field 'hostname' and my password in a field 'password'- nothing happened (including after restarting the client).

That listing isn't the lockfile is it? The one that's supposed to be deleted, followed by a reboot?

That listing isn't the lockfile is it? The one that's supposed to be deleted, followed by a reboot?

What file are you mean?
File gui_rpc_auth.cfg is represented in listing :

...
-rwxrwxrwx. 1 boinc boinc    32 Dec 16 15:23 gui_rpc_auth.cfg
...

Yes, I sometimes reboot my system (as many other users).

If the client is not running, it may be that all that means is that the manager can't connect to it.
The default port is Pi: 31416

If something else is grabbing that first, then BOINC misses out.

Otherwise, you need to use something other than the manager to see what the client is really doing.

First verify the client is even running, then worry about whether the Manager can connect to it.

Use top or htop to see the running processes and see whether boinc client is running.

Navigate to /usr/bin and open a command terminal and start the boinc client in the terminal.

Does it run and produce the normal logging output?

Or does it crash or not even run because of missing dependencies?

Use top or htop to see the running processes and see whether boinc client is running.

I used a System monitor (which allows you to make selections by the name of the process) and saw two processes: boincmgr (under the user ivan) and boinc (under the boinc user).

Navigate to /usr/bin and open a command terminal and start the boinc client in the terminal.

I forcibly terminated both boinc processes (so as not to get an error : Another instance of BOINC is running) and started the client from the folder /usr/bin and got this output:

base) [ivan@localhost ~]$ cd  /usr/bin

(base) [ivan@localhost bin]$ ls -l | grep boinc
-rwxr-xr-x   2 root root     1026920 Sep 19 01:39 boinc
-rwxr-xr-x   2 root root     1026920 Sep 19 01:39 boinc_client
-rwxr-xr-x   1 root root      334552 Sep 19 01:39 boinccmd
-rwxr-xr-x   1 root root     4123744 Sep 19 01:39 boincmgr
-rwxr-xr-x   1 root root      326200 Sep 19 01:39 boincscr

(base) [ivan@localhost bin]$ ./boinc_client
19-Dec-2020 10:35:50 [---] cc_config.xml not found - using defaults
19-Dec-2020 10:36:00 Another instance of BOINC is running.

(base) [ivan@localhost bin]$ ./boinc
19-Dec-2020 10:43:36 [---] cc_config.xml not found - using defaults
19-Dec-2020 10:43:46 Another instance of BOINC is running.

And the client didn't start even in an inactive state. The GUI application appears only when I start the manager (while it's inactive and there's no output in the console):

(base) [ivan@localhost bin]$ ./boincmgr

At the same time, not a single boinc- process appeared in System monitor.