Version 3.3.2 (3.3.2)
When I drag any of the 4 ROMs onto the preferences panel (see below) then they just "bounce back" to their original location. I cannot get the installation of the ROMS to work.

Answering own issue: you need to drag the ROM file on the actual icon (and not it's bounding box) see below

Hi Dirk, [version beta 2]
I have a problem to change the roms with drag'n'drop.
IF I drag a rom when I move a rom icon on the mac it moves well, but as soon as i enter with the icon in the VirtualC64 window to place it in the right place a great slowdown occurs, i don't know if it's the last update Apple or beta2, but previously I changed roms quickly and without problems.
...the mouse color loading wheel appears instead the black arrow and the emulation slow down.
Changing the rom after long time the reset is needed to see the changes, otherwise the Rom cannot be seen changed.
Opening the VirtualC64 preferences rom window slow down and color wheel appears.
VirtualC64_2019-08-03-095427_MacBook-Pro-di-Alessandro.cpu_resource.txt
I noticed that the slowdown happens even if I do fly over any file, without releasing the left mouse button.
If I try to move any image onto the Rom preference window of VirtualC64, VirtualC64 immediately slows down the Mac as if it wanted to analyze the file that passes over without even the left mouse button being released.
Before it was faster and this problem did not occour.
I made a video about it, if it is needed:
I made a video about it
Just watched it. I think it must be related to some refresh callback when drag and drop is active. I guess, I am doing some time-expensive stuff there.
BTW, what web browser is that? 馃槼

It looks like the browser which I used in die Middle Ages when we had to browsed the web via the telephone line and a modem 馃槄.
That browser is opensource Seamonkey, I use it ...because it has a html editor integrated that I use from the stone age...
The slow down seems to me in all the emulator preferences window...
Do you have any problem in the preferences panel of VirtualC64 ?
Solved:
Removed all about VirtualC64 and a new fresh installation.
There where some configuration files corrupted probably after update...
Removed all about VirtualC64 and a new fresh installation.
馃槸 Ooohhhh, solved by the Windows way. Apple is becoming the new Microsoft 馃槩.
Seamonkey
BTW, we need to try out Monkey Island on vAmiga 馃悞. This is where your web browser had beed developed, I guess.
https://www.seamonkey-project.org/
Is out a new version of vAmiga ?
Is out a new version of vAmiga ?
No. I'm still in a fight with the slow Blitter 馃槚. So we better wait with testing.
Overwrite the beta2 has done it.
Now all is working fine, for me you can close.
Most helpful comment
馃槸 Ooohhhh, solved by the Windows way. Apple is becoming the new Microsoft 馃槩.