Composer cannot redeclare class error

[Tyssen]

I'm getting the following error on a production site:

Quote

Error: Cannot declare class ComposerAutoloaderInit4aa8a0e5775c7445960a959e7c2ad326, because the name is already in use (line 5 of /httpdocs/site/assets/cache/FileCompiler/vendor/composer/autoload_real.php)

I don't get the error on my local version of the site.

• Why does it happen in production and not local?
• I guess it would be solved by PW not adding anything from the vendor folder to cache/FileCompiler, so how do I stop that?
• Or is there something else I should be doing to fix it?