@Christoph-Hart So what should I do? I just purchased the plugin and the dragging never worked, it crashes since day one. Should I uninstall and reinstall? If it won't work I'll have to ask for a refund. Thanks.

Good lord it worked! I selected an instrument on the left before dragging as you said and badaboom! The small glitch is provoking the crash but now we can avoid it and the dragging is working. Thank you!

@Christoph-Hart Logic pro X internal error message appears with two options to choose from (Crash or Continue), as soon as I click on the PLAY symbol or TARGET symbol of PERC X (in Edit A window, Drag), before even being able to drag and drop the midi. Thank you.

@Christoph-Hart So what should I do? I just purchased the plugin and the dragging never worked, it crashes since day one. Should I uninstall and reinstall? If it won't work I'll have to ask for a refund. Thanks.

PercX crashes when dragging midi notes into Logic pro X. I am on macOS Catalina. Please advise.

Here is the error message details:

Exception Name: NSInvalidArgumentException
Description: *** -[__NSArrayM insertObject:atIndex:]: object cannot be nil
User Info: (null)

0 CoreFoundation 0x00007fff3995db57 __exceptionPreprocess + 250
1 libobjc.A.dylib 0x00007fff727a65bf objc_exception_throw + 48
2 CoreFoundation 0x00007fff39a0c59e -[__NSCFString characterAtIndex:].cold.1 + 0
3 CoreFoundation 0x00007fff39a0a573 -[__NSArrayM insertObject:atIndex:].cold.2 + 0
4 CoreFoundation 0x00007fff3987dfb5 -[__NSArrayM insertObject:atIndex:] + 1155
5 AppKit 0x00007fff3711d594 -[NSCoreDragManager beginDraggingSessionWithItems:fromWindow:withClipRect:event:source:] + 745
6 AppKit 0x00007fff374236ad -[NSView(NSDrag) beginDraggingSessionWithItems:event:source:] + 259
7 PercX 0x000000011a6eb823 _ZN4juce20repostCurrentNSEventEv + 1053731
8 PercX 0x00000001199230cf DemoProjectAUFactory + 1581199
9 PercX 0x000000011a6c89f1 _ZN4juce20repostCurrentNSEventEv + 910833
10 PercX 0x000000011a6d15f3 _ZN4juce20repostCurrentNSEventEv + 946675
11 PercX 0x000000011a6d131e _ZN4juce20repostCurrentNSEventEv + 945950
12 PercX 0x000000011a6cbcb6 _ZN4juce20repostCurrentNSEventEv + 923830
13 Foundation 0x00007fff3bfb60dd __NSThreadPerformPerform + 204
14 CoreFoundation 0x00007fff398e1d52 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17
15 CoreFoundation 0x00007fff398e1cf1 __CFRunLoopDoSource0 + 103
16 CoreFoundation 0x00007fff398e1b0b __CFRunLoopDoSources0 + 209
17 CoreFoundation 0x00007fff398e083a __CFRunLoopRun + 927
18 CoreFoundation 0x00007fff398dfe3e CFRunLoopRunSpecific + 462
19 HIToolbox 0x00007fff3850cabd RunCurrentEventLoopInMode + 292
20 HIToolbox 0x00007fff3850c6f4 ReceiveNextEventCommon + 359
21 HIToolbox 0x00007fff3850c579 _BlockUntilNextEventMatchingListInModeWithFilter + 64
22 AppKit 0x00007fff36b52039 _DPSNextEvent + 883
23 AppKit 0x00007fff36b50880 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1352
24 Logic Pro X 0x000000010881ce00 Logic Pro X + 27622912
25 AppKit 0x00007fff36b4258e -[NSApplication run] + 658
26 AppKit 0x00007fff36b14396 NSApplicationMain + 777
27 Logic Pro X 0x00000001079bae5d Logic Pro X + 12541533
28 libdyld.dylib 0x00007fff7394ecc9 start + 1