Cannot declare class XMLParser, because the name is already in use

Hi dear community,

I am trying to access into a project in localhost (XAMPP). I have configured my base_url and my mySQL driver in the and I have ojs installed into my project with composer and Node.js.

While trying to access into “http://localhost/Jessi_Ilegal/ojs-vu/”, I get the following message in my error.log

[Tue Apr 27 09:58:43.266545 2021] [php:error] [pid 9024:tid 1852] [client] PHP Fatal error: Cannot declare class XMLParser, because the name is already in use in C:\xampp\htdocs\Jessi_Ilegal\ojs-vu\lib\pkp\classes\xml\ on line 28

Hi @Mustafa_A,

Are you using PHP 8? I suspect the OJS version you are trying to install isn’t fully compatible with it yet.


Yes I am. “8.0.3 Thread Safe”

Shall I remove php 8 and reinstall into php7?

Thank you for replaying on me.

I love Pink Floyd :smiley:

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Yes. it depends on the OJS version that you are using. PHP 7.3 probably covers most of the recent OJS versions.

I have a last question.

I am using XAMPP and it has " PHP Version 8.0.1" in it.

Do I need to pick up an older version of XAMPP in order to have PHP 7.3?

or do I need to change my local installation of PHP on C:\php ?

If OJS runs on XAMPP, then the one that it uses. I don’t think you need to re-install the whole XAMPP, only PHP.

Dear friend, thank you again for being so helpful.

I have done what u just told me to. I have another XAMPP7 in my C drive and the issue has been solve.

Now I am getting another error message saying

" Database connection failed!"

[Tue Apr 27 16:50:05.873990 2021] [php7:notice] [pid 12160:tid 1816] [client] ojs2: Database connection failed!

any good advice?

Can you check if your database server (MariaDB) is running and database credentials are correct? PHP7+ uses mysqli driver and it’s usually shipped with distribution.

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Closing as the issue is solved and additional question is duplicated in the new forum thread: Ojs2: Database connection failed!

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