Unable to open Zynaddsubfx and vsts

[Rakso]

For whatever reason LMMS suddenly stopped being able to open vst plugins as well as zynaddsubfx. I am able to hear sounds made with zyn and I'm able to add fx to it etc but as soon as I try to open the actual zynaddsubfx GUI to edit the sound LMMS crashes.

Does anyone have any idea on how to fix or has anyone experienced something similar?

I've heard zynaddsubfx is technically some sort of embedded vst so the problems are propably related.

EDIT: I use windows 10. I also recently used a "Pc optimisation tool" called Slimcleaner to speed up my computer. It basically deletes unnesesarry junk and defragments the disk etc. It's worked quite well but I'm just wondering if it deleted something not-so-unnecessary (something thats needed for opening vsts).

EDIT number 2:

I tried to open RemoteVstPlugin.exe and it had the following error message: "The program can't start because QtCore4.dll is missing from your computer. Try reinstalling the program to fix this problem"

I also tried opening RemoteZynAddSubFx.exe and it said "The program can't start because libfltk.dll is missing from your computer. Try reinstalling the program to fix this problem"

So I will try to install those those programs and see if it works. I guess my Pc optimization tool just thought their useless or something. If not idk how they are not on my computer/dissapeared from my computer.

[musikbear]

looks like you already both know the reason, and how to fix it, so i guess im here to say : good luck :p
Nahh actually i will say De-install, dl a fresh new win64lmms, and do a clean installation. no reason to try to 'patch' lmms with the missing files, cause then you will properly just get a miss-flag from something else
...Now i just hope for your sake, that lmms is the only proggy your 'optimization-tool' has demolished

[Rakso]

Weirdly enough the problem was gone after restarting my computer XD. I later checked and all the "missing" .dll files were there. So idk what happened. Oh well, the problems gone at least now (for forever, lets hope).