Where do I find presets in Lightroom Classic and know how to install them?

"When i click the + sign next to presets nothing happens."

Make sure you have a photo selected in Develop before clicking the "+" button -- otherwise it is ignored (a silly buglet in LR).

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Sounds like your preferences file is corrupt. You may need to reset it. By reset Adobe means delete and allow Lightroom to recreate.

This one of at least two magic bullets, the other being a reboot.

see and understand the following links

https://helpx.adobe.com/lightroom-classic/help/setting-preferences-lightroom.html

https://lightroomers.com/replacing-the-lightroom-preference-file/745/

https://www.youtube.com/watch?v=bARt-hoCc2Q

https://helpx.adobe.com/lightroom-classic/kb/recover-catalog-images-resetting-lightroom.html

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Hi there,

That's not a usual experience,  let's work to isolate what you're seeing.

To start with, I'd recommend that you checkout the below article to endure that you are looking for the presets in the right menu:

https://helpx.adobe.com/in/lightroom-classic/help/develop-module-tools.html#create_and_apply_develop_presets

Let us know if that helps.

Thanks,

Akash