Settings-Journal in backend loads forever....and nothing

Hello. Good afternoon. I noticed a problem in my OJS 3.1.0.0 installation some days ago. Settings-Journal in backend loads forever, after a while I get a “504 Gateway Time-out. The server didn’t respond in time” message, and the same happens in website Settings - Plugins gallery. The other pages load fast and perfect.

In Cpanel´s error log i can´t read anything related with OJS folder.

In Chrome´s console i Have this…

It worked fine before, I have no changed anything in cpanel or files so I don´t understand what happen. Any clue? Thanks