The link below is the official introduction from phpBB.com
Here I listed what problem I met and how I solved:
1, when use stk to clear the database, need to set maximum_time_out to large if it is 30. I set to 60, it works file.
2, After copied the files of phpBB 3.2.5 to the root folder and press ‘http://xxx/install’, it shows no mySQL_connection.
Since PHP 7.0, mySQL_connection function was removed. If it is on PHP7.0, change database driver from ‘mysql’ to ‘mysqli’ on the config.php file.
If the web server is on your computer, you need to change a few folders permission to 777. Those folders are files, cache, store. In phpBB 3.0, no store folder, build one.
3, After upgraded, couldn’t find permission page.
Clear the cache. Open ACP, on the default page, click ‘run now’ next ‘Purge cache’ to clear cache.
For me, it showed another error:
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/zendframework/zend-stdlib/src/ArrayObject.php on line 426: “continue” targeting switch is equivalent to “break”. Did you mean to use “continue 2”? …..
It’s said that phpBB 3.2.5 is not compatible with php 7.3. I changed to php 7.2, it is ok then.
4, On my macbook, when I change the Edit Forum page in ACP, it shows:
This site can’t be reached. ERR_CONNECTION_RESET.
I used my smart phone, it worked well.
5, the website is flooded by spams.
At ACP, the ‘General > User registration settings’ page, change the general setting to stop it. E.g.: New member post limit.