Technical issue occured possibly due to bad network connection

After upgrading to version 6.2.4 we have troubles. When we try to open an existing record or click create new button we got an error:
"Technical issue occured possibly due to bad network connection.
Please try again.
If issue persists, please contact your administrator."

There is nothing in log file. And in apache log i've:
[Wed May 17 11:44:58 2017] [error] File does not exist: /xxx/projeqtor/external/promise, referer: http://xxx/projeqtor/view/main.php
We dont have promise directory really. I tried to download source code for several times and never recieve such a directory.

I've tried with many browsers all the same. In browser consolo log i've:
Error on xhrPost return for loadContent('objectDetail.php?destinationWidth=1645&destinationHeight=104&isIE='&#44; 'detailDiv'&#44; '[object HTMLFormElement]'&#44; 'undefined') : <br/> RequestError: Unable to load objectDetail.php?destinationWidth=1645&destinationHeight=104&isIE= status: 0
projeqtor.js (831,13)

I tried your online demo, it works.
I've set max_input_vars to 4000 in php.ini.
We dont have any customizations in model/custom diectory.
I don't know what to check more?

Yes i ve error on browser console. It is written in my message.
Microsoft Edge Error:
Error on xhrPost return for loadContent('objectDetail.php?destinationWidth=1645&destinationHeight=104&isIE=', 'detailDiv', '[object HTMLFormElement]', 'undefined') : <br/> RequestError: Unable to load objectDetail.php?destinationWidth=1645&destinationHeight=104&isIE= status: 0
projeqtor.js (831,13)

Firefox Error:
Error on xhrPost return for loadContent('objectDetail.php?destinationWidth=1334.4&destinationHeight=501.4&isIE='&#44; 'detailDiv'&#44; '[object HTMLFormElement]'&#44; 'undefined') : <br/> RequestError: Unable to load objectDetail.php?destinationWidth=1334.4&destinationHeight=501.4&isIE= status: 0

Ok this is full error text:

=> 863ms | page='objectMain.php' | destination='centerDiv' (server:144ms, client:719ms)
projeqtor.js (76,3)
SCRIPT7002: XMLHttpRequest: Ağ Hatası 0x800c0007, İstenilen kaynak için kullanılabilir bir veri yok.

main.php
Error on xhrPost return for loadContent('objectDetail.php?destinationWidth=1325&destinationHeight=0&isIE='&#44; 'detailDiv'&#44; 'listForm'&#44; 'undefined') : <br/> RequestError: Unable to load objectDetail.php?destinationWidth=1325&destinationHeight=0&isIE= status: 0
projeqtor.js (831,13)
RequestError: Unable to load objectDetail.php?destinationWidth=1325&destinationHeight=0&isIE= status: 0
dojo.js (2,103057)
{
[functions]: ,
__proto__: { },
message: "Unable to load objectDetail.php?destinationWidth=1325&destinationHeight=0&isIE= status: 0",
name: "RequestError",
response: {
[functions]: ,
__proto__: { },
options: { },
status: 0,
text: "",
url: "objectDetail.php?destinationWidth=1325&destinationHeight=0&isIE=",
xhr: {
[functions]: ,
__proto__: { },
DONE: 4,
HEADERS_RECEIVED: 2,
LOADING: 3,
msCaching: "auto",
onabort: null,
onerror: null,
onload: null,
onloadend: null,
onloadstart: null,
onprogress: null,
onreadystatechange: null,
ontimeout: null,
OPENED: 1,
readyState: 4,
response: "",
responseText: "",
responseType: "",
responseURL: "",
responseXML: null,
status: 0,
statusText: "",
timeout: 0,
UNSENT: 0,
upload: { },
withCredentials: false
}
},
responseText: "",
stack: "Error: Unable to load objectDetail.php?destinationWidth=1325&destinationHeight=0&isIE= status: 0
at _4a6 (test.proje.com/k/projeqtor/external/dojo...V6.2.4.0168:2:125468)
at _32a (test.proje.com/k/projeqtor/external/dojo...=V6.2.4.0168:2:84994)",
status: 0,
xhr: { }
}

"If no error is displayed, check for network tab and look for response of request raising the issue (it is request to objectDetail.php). Send us this response."

response to this request in network tab is this:

<div dojoType="dijit.layout.BorderContainer"> <div id="buttonDiv" dojoType="dijit.layout.ContentPane" region="top"
style="z-index: 3; height: 35px; position: relative; overflow: visible !important;">
<div id="resultDiv" dojoType="dijit.layout.ContentPane" region="top"
style="display: none;z-index:99999;"></div>
<table style="width:100%;height:100%;">
<tr style="height:100%";>
<td style="z-index:-1;width:40%;white-space:nowrap;">
<div style="width:100%;height:100%;">
<table style="width:100%;height:100%;">
<tr style="height:35px;">
<td style="width:43px;">&nbsp;
<div style="position:absolute;left:0px;width:43px;top:0px;height:36px;" class="iconHighlight">&nbsp;</div>
<div style="position:absolute; top:0px;left:5px ;" class="iconResource32" style="margin-left:9px;width:32px;height:32px" /></div>
</td>
<td class="title" style="width:10%;">
&nbsp;Resource<span id="buttonDivObjectId">&nbsp;#40&nbsp;</span>
</td>
<td class="title" style="height:35px;">
<div style="width:100%;height:100%;position:relative;">
<div id="buttonDivObjectName" style="width:100%;position:absolute;top:8px;text-overflow:ellipsis;overflow:hidden;">
&nbsp;-&nbsp;XXX TEst </div>
</td>
</tr>
</table>
</div>
</td>
<td style="width:8%; text-align:right;" >
<div style="width:120px;margin-right:16px;" id="buttonDivCreationInfo"><div style="float:left;">
</div>
<div style="paddin