Cannot install plugin from plugin gallery after upgrade to 3.1

[kawahyu]

Dear all,
I got the following notification when installing plugin from plugin gallery

@asmecher

[Ph_We]

Would this help?

OJS 3.1. No Quick Submit Plugin in plugin gallery

Hi @OSU and @t4x0n, A slight correction – I did have to tweak a little bit of code in OJS to get this all working as it should. After following the upgrade directions, your OJS install will be left with an entry in the database for the plugins you’ve installed through the Plugin Gallery before, but the plugins won’t be present in your filesystem. Thus OJS as released will report that the plugin is already present and up to date, even though it isn’t. To get it to permit you to re-install the …