Autoload error '(Module Name)' component already exists

[Alex70]

Hello
I'm stuck with my Web site as I wrongly installed the same module twice. In detail:
Magento is at 2.0.5
I recently installed Henhed_Piwik module manually coping the code under app/code...... all was working properly...
Today I read that it's a good practise to install any modules using composer for a faster updating process. So I decided to reinstall it with composer thinking it would overwrite the previous one.....
Composer did install it but now when I try to access to the website I'm alerted with this message:
Autoload error
'Henhed_Piwik' component already exists

Can you please help me resolving this issue

Thanks

[Pektsekye · Accepted solution]

Hello,

Try to delete all files from app/code/Henhed

And all database tables of this extension. You can find them in:

app/code/Henhed/Piwik/Setup/InstallSchema.php

And "Henhed_Piwik" entry from the "setup_module" database table.

Then run:

bin/magento setup:upgrade

Stanislav

[Alex70 · Accepted solution]

Thanks Stanislav.....

Your suggestion may work.... Anyway I did before your post  in another way.... 

I'm reporting here follow the solution just for reference for someone else...

01) delete or move out from Magento Root the module folder. In my case the folder was "Henhed" in magentoroot/app/code/

02) delete or move out all the content of the magentoroot/var  folder

03) go to the magento root folder

04) run the command: chmod 777 * -R

05) run the command: bin/magento module:disable Henhed_Piwik

06) run the command: bin/magento module:uninstall Henhed_Piwik -r -c

       This command stuck at the step "Removing code from Magento codebase:"

       Stop this process with the cntr+x 

07) run the command: composer update

       This command will automatically remove the module from composer.json and from vendor folder.

08) run the command: bin/magento setup:static-content:deploy

09) run the command: bin/magento setup:di:compile

10) run the command: find . -type d -exec chmod 770 {} \; && find . -type f -exec chmod 660 {} \; && chmod u+x bin/magento

11) run the command: bin/magento maintenance:disable

12) run the command: bin/magento cache:clean

This has resolved the issue at all .....

[WorldNet TPS]

Hi,

Very informative and clear solution, thank you for posting this.  Its working fine  but I am not able to see my payment module on frontend checkout page.  Below is my issue,

" I am trying simple offline payment module, I dropped the files in app/code folder, It's working for backend part but its not showing on frontend checkout page. I search and came to know that I need to Install my module via composer,  I tried that and followed your steps but still the same issue persist. "

Can you please help me what should I do to see my module on checkout page. I have full working directory with js files and there is no compilation error.  Please help me in this.

Thanks

[WorldNet TPS]

Hey,

Can you please help me in this regards.

Thanks