Hi @Jonas_Henryz and welcome. As @dylan mentioned this has been reported before: Roon crashes while adding more than 20 bands in DSP Parametric EQ and number 20th is a parameter too far. @Jonas_Henryz I get the impression that you’d like to try to rescue your settings? If you’re reasonably computer literate, can use the terminal on your Mac, I think that it’s possible to rescue these.
I’ve not got a Mac core installation, I run a Linux install, but on that there’s a directory called /var/roon/RoonServer/Database/Registry/Core. It’ll almost certainly be elsewhere on the mac, you could use the command line find utility, something like find / -type d -name "RoonServer" should narrow the field.
In this directory I have a text/JSON file called endpoint_parametric_equalizer_presets, mine looks like something like this, I’ve added indentation and chopped some to make it easier:
{
"version":1,
"presets":[{
"name":"Proto House Curve",
"data":{
"bands":[
{"type":"equalize_frequency",
"frequency":100,
"gain_db":3,
"q":1,
"is_enabled":true},
{"type":"low_shelf",
"frequency":200,
"gain_db":1.5,
"q":1,
"is_enabled":true},
{"type":"equalize_frequency",
"frequency":1000,
"gain_db":2.1,
"q":1,
"is_enabled":true},
{"type":"high_shelf",
"frequency":2000,
"gain_db":-1.5,
"q":1.05,
"is_enabled":true},
{"type":"high_shelf",
"frequency":8318,
"gain_db":-2.4,
"q":1,"is_enabled":true},
{"type":"high_pass",
"frequency":20,
"order":1,
"is_enabled":false},
{"type":"low_pass",
"frequency":20000,
"order":1,
"is_enabled":false}],
"gain_db":0,
"y_axis_min_db":-12,
"y_axis_max_db":12}}
...
]
}
You can at least read that bands you took time over and recreate the eq settings, please stop at 19 bands this time 
.
If you were feeling brave you could create a copy and try editing the last band out, it may then work. My worry is if you get it wrong things might get worse. See how you get along with the first part and give a shout if you’re contemplating the edit solution but need some help, or any other questions come to that.
Good luck…