Logic Still Loads Instruments and Tracks after I've Deleted Them

Hi.

Could anyone please help me with the following issue?

In a Logic Pro X project, I had multiple tracks with numerous Logic MIDI and 3rd-party software instruments, plus a lot of audio takes of guitars, bass, vocals.

Yesterday, I decided to start from scratch and deleted all those unnecessary tracks, to find a new sound for the project with a fresh approach and new instruments. As a result of that decision, I only left 8 tracks. And this is where the problem began.

Now that I quit and reopen the project, it still shows the loading process for all those previous software instruments and audio takes, even though they're no longer assigned to any of the remaining tracks - I deleted them all. Even worse - if some of the previous 3rd-party instruments were from a sound library that I once had on an external hard drive, Logic now displays a missing files error, since that drive is no longer connected.

The worst bit is that, regardless of the current 8 tracks and a seemingly light project, Logic thinks the project is still heavily loaded with the previous multitude of tracks and suddenly freezes every time I try to play it. Force-quitting, restarting the mac, resetting PRAM - none of these have helped. Any ideas, please?

How do I go about this?