Report module - empty chart image with empty labels array in canvas

When I get an empty canvas image I can’t find any logic in this issue.

Now I see the error comes from Canvas object.
In console I see the error
“index.php?module=AOR_Reports&action=DetailView&record=4685ebba-533b-d89d-261f-5d2f42ba2096:1186 Uncaught SyntaxError: Unexpected token ,”
And I see in Canvas object no array for variable Labels, populated with javascript:

new RGraph.Bar({
            id: '740a2c8b-c527-8c6c-5f73-5d8a21cb8f41',
            data: [82,39,28,16,12,11,10,8,7,3,3,1,1,1,1,1],
            options: {
            title: '',
                gutterBottom: 150,
                gutterLeft: 128,
                gutterTop: 25,
                //title: '',
                textAngle: 90,

                tooltips:["\u010cesk\u00e9 vysok\u00e9 u\u010den\u00ed technick\u00e9 v Praze: 82","N\u00e1rodn\u00ed technick\u00e1 knihovna: 39","Vysok\u00e1 \u0161kola chemicko-technologick\u00e1 v Praze: 28","Ostatn\u00ed ve\u0159ejnost: 16","Ostatn\u00ed V\u0160: 12","\u010cesk\u00e1 zem\u011bd\u011blsk\u00e1 univerzita v Praze: 11","Univerzita Karlova: 10","Anadolu University in Eski\u015fehir: 8","Rakousk\u00e9 gymn\u00e1zium v Praze: 7","Vysok\u00e1 \u0161kola ekonomick\u00e1 v Praze: 3","CESNET, z. s. p. o.: 3","Univerzita Palack\u00e9ho v Olomouci: 1","Jin\u00e1 S\u0160: 1","Masarykova univerzita: 1","Ostatn\u00ed S\u0160: 1","Slovensk\u00e1 n\u00e1rodn\u00e1 kni\u017enica: 1"],
                tooltipsCssClass: 'rgraph_chart_tooltips_css',

                colors: ['#b26430','#e5fce0','#754646','#a4f307','#05849a','#960fca','#9427e8','#fa4526','#c42e5d','#9fe1f6','#8507ed','#c6ce80','#b99d07','#03f6ac','#f1d72c','#ed5b3d'],

The problem happens more often with Account

My 1st idea was it happens because too many rows. I chaned conditions and I saw the bar chart if less then 30 records.
But I can see bar chart with much more records in other reports for different modules.

My second idea is the problem with text labels.
If I change label field to count it works well with more then 80 records.
But the same time I can use ID. But ID is a text variable with very long name.

The final idea is that organization name in UTF8 in non latin language.
But for latin names I have the same issue.
Also I can use Assigned to and it works with names in non latin.

More - if I use base other modul then the Account, then I have the same issue with Accoun Name field in a chart.
Thus I have no ideas how to solve it for account name field or member of name field.

PS: I do a lot of Repair and Rebuild.