"A problem occurred"

I’m working on this new font and i get the following message
Please help us to fix it by copying the following text and pasting it into a new post on https://forum.glyphsapp.com. Thanks!

text: ’
ببب
ﺣ’ (__NSCFString), length: 7, string: ‘ج{
}’ (NSConcreteAttributedString), length: 1, range: {8, 0}

NSRangeException

NSMutableRLEArray insertObject:range:: Out of bounds

(
“3 Foundation 0x00007fff57d6a563 -[NSMutableRLEArray insertObject:range:] + 151”,
“4 Foundation 0x00007fff57d6b0df -[NSConcreteMutableAttributedString replaceCharactersInRange:withAttributedString:] + 242”,
“5 Glyphs 0x000000010bd40f36 Glyphs + 335670”,
“6 AppKit 0x00007fff533648c5 -[NSTextInputContext(NSInputContext_WithCompletion) insertText:replacementRange:completionHandler:] + 75”,
“7 AppKit 0x00007fff53bf65f5 __55-[NSTextInputContext handleTSMEvent:completionHandler:]_block_invoke_2.385 + 109”,
“8 AppKit 0x00007fff53364874 -[NSTextInputContext do_HandleTSMEvent_insertFixLenTextLoop:whileCondition:dispatchWorkEach:afterEachInsertText:continuation:] + 110”,
“9 AppKit 0x00007fff53bf456d -[NSTextInputContext tryHandleTSMEvent_insertFixLenText_withContext:dispatchCondition:setupForDispatch:nestedWorkaroundCondition:nestedWorkaroundDispatchWork:loopCondition:dispatchWorkEach:afterEachInsertText:continuation:] + 320”
)