WampServer

Setup Information:
1 - Windows 8.1 Professional - 64 bit

2 - WAMPServer Version 2.5 - 64 bit

3 - Apache Version 2.4.9

4 - PHP Version 5.5.12

4a - phpMyAdmin Version 4.3.9

5 - MySQL Version 5.5.40

6 - WampServer icon is Orange

wampmanager.conf (in c:/wamp/)
[mysql]
mysqlVersion = "5.5.40"

mysqlLastKnown = "5.6.17"

mysqlConfDir = "."

mysqlConfFile = "my.ini"

mysqlExeDir = "bin"

mysqlExeFile = "mysqld.exe"

mysqlServiceInstallParams = "--install-manual wampmysqld64"

mysqlServiceRemoveParams = "--remove wampmysqld64"

config.inc.php (in C:/wamp/apps/phpmyadmin4.3.9/)
$cfg['Servers'][$i]['user'] = 'root';
$cfg['Servers'][$i]['password'] = '***************'; <- password in actual file
/* Server parameters */
$cfg['Servers'][$i]['host'] = '127.0.0.1';
$cfg['Servers'][$i]['connect_type'] = 'tcp';
$cfg['Servers'][$i]['compress'] = false;
/* Select mysql if your server does not have mysqli */
$cfg['Servers'][$i]['extension'] = 'mysqli';
$cfg['Servers'][$i]['AllowNoPassword'] = true;

my.ini (in C:/wamp/bin/mysql/mysql5.5.40/)
[wampmysqld]
port = 3306
socket = /tmp/mysql.sock
skip-external-locking
key_buffer_size = 16M
max_allowed_packet = 1M
table_open_cache = 4
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
net_buffer_length = 2K
thread_stack = 128K
myisam_sort_buffer_size = 8M
basedir=c:/wamp/bin/mysql/mysql5.5.40
log-error=c:/wamp/logs/mysql.log
datadir=c:/wamp/bin/mysql/mysql5.5.40/data
lc-messages-dir=c:/wamp/bin/mysql/mysql5.5.40/share


What is successful?
Selecting MySQL 5.6.17 or 5.6.21 gives green Icon and success view MySQL database via phpMyAdmin
The following versions are all present in WAMPServer->MySQL->Version:
5.5.32, 5.5.40, 5.6.17, 5.6.21

What fails?
Select MySQL 5.5.32 or 5.5.40 gives orange Icon and failure viewing MySQL database via phpMyAdmin
Receive the following error when Clicking on phpMyAdmin link:
Error
MySQL said:

Cannot connect: invalid settings.

phpMyAdmin tried to connect to the MySQL server, and the server rejected the connection.
You should check the host, username and password in your configuration and make sure that they correspond to the information given by the administrator of the MySQL server.


What I've done so far?
I followed the procedure listed in WAMPServer Forum:
Re: How to add MySQL to the switch? new
Posted by: RiggsFolly (---.as43234.net)
Date: February 07, 2015 03:23PM
HowTo: Install a new version of MySQL into wamp and migrate your data properly.

mysql upgrade fails with no real error:
mysql upgrade_results.txt
Looking for 'mysql.exe' as: C:\wamp\bin\mysql\mysql5.5.40\bin\mysql.exe
Looking for 'mysqlcheck.exe' as: C:\wamp\bin\mysql\mysql5.5.40\bin\mysqlcheck.exe


Questions:
- Does MySQL 5.5.* support mysqli extension?
Do I need to comment out the following line in config.inc.php?:
$cfg['Servers'][$i]['extension'] = 'mysqli';

- What are my next steps to figure out what's wrong?

More...

Received the following messages in event viewer:
Level Source Event ID Detail
Information MySQL 100 Plugin 'FEDERATED' is disabled
Error MySQL 100 Plugin 'InnoDB' init function returned error.
Error MySQL 100 Plugin 'InnoDB' registration as a STORAGE ENGINE failed
Error MySQL 100 Plugin 'InnoDB' Unknown/unsupported storage engine: InnoDB
Error MySQL 100 Aborting
Information MySQL 100 wampmysqld64: Shutdown complete

Is this telling me the conents of the ...mysql5.5.40/data directory, i.e. what I copied here from the ...mysql5.6.17 directory, is not compatible with mysql5.5.40 application?
I know I followed the process you described for upgrading MySQL, when in fact I am 'downgrading' to a prior version.
Should I follow another process for downgrading to a prior level of MySQL and if so, what is that process or where can I find it?

Just learning to use WAMPServer...am learning a lot, but I know I have a lot more to learn about it.
Thanks for any help you can give me.

Jmwright1058

More...

Some success:
I re-installed MySQL5.5.32.

This time I did NOT copy the data directory contents from mysql5.6.17 over the top of the data directory in 5.5.32.

I copied the wampserver.conf file from ...mysql5.6.17 to ...mysql5.5.32

I then removed the password from ...phpmyadmin4.3.9/config.in.php.

I then did a WAMPServer refresh, which revealed the newly installed mysql5.5.32

I then exited and re-started WAMPServer

Now, when I clicked on the phpMyAdmin link, it came up, but displayed the message indicating mysql database did not have a password and recommended I set one... which I did!

Fantastic! I'm off and running again.

Thanks at least for anyone that was day-dreaming an answer to my issue, cause it helped!