App Crashing on expandableTableView(_:expandedCellsForRowAt:)

[bebslab]

Firebase report a non recurrent crash. It appears randomly.

This is the crashlytics report:

Fatal Exception: NSRangeException
*** -[__NSArrayM objectAtIndexedSubscript:]: index 18446744073709551615 beyond bounds [0 .. 9]
Controller.expandableTableView(_:expandedCellsForRowAt:)

Fatal Exception: NSRangeException
0 CoreFoundation 0x18ab5986c __exceptionPreprocess
1 libobjc.A.dylib 0x19fb72c50 objc_exception_throw
2 CoreFoundation 0x18abc9e1c -[__NSCFString characterAtIndex:].cold.1
3 CoreFoundation 0x18aa47e8c -[__NSDictionaryI objectForKeyedSubscript:]
4 Souffleur de Rêves 0x102a428e4 AudioListController.expandableTableView(:expandedCellsForRowAt:) + 1218 (AudioListController.swift:1218)
5 ExpandableCell 0x103197a20 ExpandableTableView.open(indexPath:delegate:) + 111 (ExpandableTableView.swift:111)
6 ExpandableCell 0x103197280 ExpandableTableView.handleRowExpansion(at:) + 91 (ExpandableTableView.swift:91)
7 ExpandableCell 0x103196f00 ExpandableTableView.tableView(:didSelectRowAt:) + 65 (ExpandableTableView.swift:65)
8 ExpandableCell 0x103197358 @objc ExpandableTableView.tableView(_:didSelectRowAt:) ()
9 UIKitCore 0x18d721830 -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:isCellMultiSelect:]
10 UIKitCore 0x18d7213d8 -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:]
11 UIKitCore 0x18d721b98 -[UITableView _userSelectRowAtPendingSelectionIndexPath:]
12 UIKitCore 0x18d9f7544 -[_UIAfterCACommitBlock run]
13 UIKitCore 0x18d51f00c _runAfterCACommitDeferredBlocks
14 UIKitCore 0x18d50d9a0 _cleanUpAfterCAFlushAndRunDeferredBlocks
15 UIKitCore 0x18d541bb4 _afterCACommitHandler
16 CoreFoundation 0x18aad4358 CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION
17 CoreFoundation 0x18aace5c4 __CFRunLoopDoObservers
18 CoreFoundation 0x18aaceb74 __CFRunLoopRun
19 CoreFoundation 0x18aace21c CFRunLoopRunSpecific
20 GraphicsServices 0x1a2698784 GSEventRunModal
21 UIKitCore 0x18d50eee8 -[UIApplication _run]
22 UIKitCore 0x18d51475c UIApplicationMain
23 Souffleur de Rêves 0x1029f6b74 main + 32 (UIColor+Set.swift:32)
24 libdyld.dylib 0x18a78e6b0 start

An undefined index is applied.

If someone can help me to solve this crash issue. Thank you