"Failed Ajax request or invalid JSON returned" errors on Turkish backend

Hi @asmecher

In order to reproduce those errors, I generated an identical test site with identical database, and identical ojs3 files. I only changed config.inc.php.
http://ojs3.adlitipbulteni.com

I can generate the same errors on test site. Wnen I enabled show_stacktrace = On, and display_errors = On in the config file, no submissions are listed. When I click Issues, that error message is displayed at backend
Warning: assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
So enabling only show_stacktrace = On in the config file, I get those lines at php56.log;

[25-May-2017 04:55:22 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 04:55:22 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 14:55:26 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:26 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 04:55:26 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 04:55:26 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 14:55:27 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:27 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:27 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:27 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:27 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:27 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:27 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:27 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:27 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:27 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:37 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:37 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:37 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:37 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:37 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:37 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:37 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:37 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:37 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:37 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:40 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:40 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:42 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:42 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:43 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:43 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:46 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:46 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:47 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:47 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:47 Europe/Istanbul] ASSERTION FAILED ON informationCenter
[25-May-2017 14:55:47 Europe/Istanbul] PHP Warning:  assert(): Assertion failed in /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPString.inc.php on line 838
[25-May-2017 14:55:47 Europe/Istanbul] ojs2: 404 Not Found
[25-May-2017 04:55:55 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133

[25-May-2017 04:55:56 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 14:55:56 Europe/Istanbul] ojs2: 404 Not Found
[25-May-2017 04:55:57 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133

[25-May-2017 04:55:59 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 14:56:06 Europe/Istanbul] ojs2: 404 Not Found
[25-May-2017 04:56:06 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 04:56:06 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133

[25-May-2017 04:56:09 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133
[25-May-2017 14:56:11 Europe/Istanbul] ojs2: 404 Not Found
[25-May-2017 04:56:24 America/Los_Angeles] PHP Warning:  Cannot use a scalar value as an array in /home/ugukoc/adlitipbulteni.com/lib/pkp/classes/core/DataObject.inc.php on line 133

Note: I removed several duplicate lines to save some space.

At the same moment, I get those errors at Safari inspector console,
http://ojs3.adlitipbulteni.com/index.php/atb/$$$call$$$/modals/submission-metadata/Issue-entry/fetch?submissionId=1047&stageId=3&=1495713341081
Failed to load resource: the server responded with a status of 404 (Not Found)
http://ojs3.adlitipbulteni.com/index.php/atb/$$$call$$$/center/submission-Information-center/view-Information-center?submissionId=1047&
=1495713341082
Failed to load resource: the server responded with a status of 404 (Not Found)
http://ojs3.adlitipbulteni.com/index.php/atb/$$$call$$$/center/file-Information-center/view-Information-center?fileId=4538&revision=1&submissionId=1047&stageId=3&=1495713341083
Failed to load resource: the server responded with a status of 404 (Not Found)
http://ojs3.adlitipbulteni.com/index.php/atb/$$$call$$$/modals/editor-decision/editor-decision/send-reviews-In-review?submissionId=1047&stageId=3&reviewRoundId=380&decision=3&
=1495713341084
Failed to load resource: the server responded with a status of 404 (Not Found)
When I click the links above, I got this errors at the opened web page;
404 Not Found

Stack Trace:

File: /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPRouter.inc.php line 356
Function: Dispatcher->handle404()

File: /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPComponentRouter.inc.php line 262
Function: PKPRouter->_authorizeInitializeAndCallRequest(Null, Object(Request), Array(3))

File: /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/Dispatcher.inc.php line 134
Function: PKPComponentRouter->route(Object(Request))

File: /home/ugukoc/ojs3.adlitipbulteni.com/lib/pkp/classes/core/PKPApplication.inc.php line 227
Function: Dispatcher->dispatch(Object(Request))

File: /home/ugukoc/ojs3.adlitipbulteni.com/index.php line 68
Function: PKPApplication->execute()

Best Regards,
Ugur