I'm assuming that you can't actually get OBS Studio to start at all?
You've got a couple of options here neither of which are necessarily great.
1) delete all of your configuration, do this by Choosing Start, Run type %appdata% then press return. Scroll down in the list of folders until you see obs-studio, right click choose rename and then change the name to obs-studio-old. Try running OBS MP and see if it works. Downside of this is that you've lost all your scenes and other configuration :-(
2) You can try and find the crop filter in your config files but I would not recommend this unless you are handy with text editors and a little familiar with JSON. Seriously though I accept no responsibility if this doesn't help, you'll have your backup in case you need to get back to a known scenario be very careful and very sure of what you are doing and if you are at all uncomfortable you might just be better going with Option 1) and recreating all your scenes, settings and sources. You need to find the scene you were working with, look in %appdata%\obs-studio\basic\scenes. There are several files in here but the one you want is called "scene-name".json. First take a copy of this file and put it on your desktop. OK we have a backup :-) Edit the file in something like notepad++, Windows notepad will not be good enough. Each crop filter has some lines like this:
"filters": [
{
"enabled": true,
"flags": 0,
"hotkeys": {},
"id": "crop_filter",
"mixers": 0,
"muted": false,
"name": "Text Crop",
Note this last entry is the name you called the crop filter, there may be multiple crop filters in the same file. You now need to delete the filter. Very carefully select all the text from and including the " before filters and the first occurrence of ], after that you can find. The section looks like this with all the information taken out:
"filters": [
{
<data>
}
],
Delete this section and save the file and then try and restart OBS studio. Obviously if you have multiple crop filters you may need to delete multiple sections. If deleting the first one doesn't work restore your backup from your desktop and then try removing the second crop filter and so on.
Let me know if this helps you get OBS working or if you need some further help.