Here is the history.
My site was using OJS 3.0.2. I upgraded it to 3.1, and it is looking great, besides this error.
When I click in Submissions, everything is ok:

But when i click on the box to search for some submission:

The it dont work anymore.
Here is the debug. When i click submissions, nothing wrong:

When I click on the search box, this are the changes.

Any helps are apreciated.
HI @Hugo_Melo
Did you check your console log and your php error log to check if there is some message about this event?
Regards,
Israel Cefrin
Public Knowledge Project Team
Got this:
Strict Standards: Declaration of DRIVERDAO::setOAI() should be compatible with PKPOAIDAO::setOAI($oai) in /home/dpgpsifp/psicodebate.dpgpsifpm.com.br/plugins/generic/driver/DRIVERDAO.inc.php on line 19
Strict Standards: Declaration of SubmissionFileDAO::fromRow() should be compatible with PKPSubmissionFileDAO::fromRow($row, $fileImplementation) in /home/dpgpsifp/psicodebate.dpgpsifpm.com.br/classes/article/SubmissionFileDAO.inc.php on line 23
Warning: Cannot modify header information - headers already sent by (output started at /home/dpgpsifp/psicodebate.dpgpsifpm.com.br/plugins/generic/driver/DRIVERDAO.inc.php:19) in /home/dpgpsifp/psicodebate.dpgpsifpm.com.br/lib/pkp/classes/template/PKPTemplateManager.inc.php on line 855
Warning: Cannot modify header information - headers already sent by (output started at /home/dpgpsifp/psicodebate.dpgpsifpm.com.br/plugins/generic/driver/DRIVERDAO.inc.php:19) in /home/dpgpsifp/psicodebate.dpgpsifpm.com.br/lib/pkp/classes/template/PKPTemplateManager.inc.php on line 856
@Hugo_Melo
Something is being printed to the output buffer before the search request is written, which is causing an invalid response from the REST API.
This situation is often caused by some error (like a PHP Notice) that’s getting printed to the output buffer (and generates that warning either).
A possible and quick approach to handle it is check XHR response in Chrome’s dev tools.


Regards,
Israel Cefrin
Public Knowledge Project Team
It is getting 2 answers:


However it is showing this 4 errors:

Not a clue of what to do next. Can it be cause of a bad upgrade?