Hi @ozgur,
These warnings can be ignored.
Please:
# . /etc/profile.d/kaltura-base.sh
and then run:
# kaltlog
in parallel to making the HTTP requests to see what errors are logged. Then, go to the actual log file, would usually be either /opt/kaltura/log/kaltura_api_v3.log or /opt/kaltura/log/kaltura_apache*errors.log and look at the lines leading to the actual error. Also, open your browser's devtools and look at the "Console" and "Network" tabs for errors and bad HTTP requests.