Insert into post buttom always inactive

Thank you for reply
kaltlog shows nothing and Browser dev tools shows
Uncaught SyntaxError: Unexpected end of JSON input
at JSON.parse ()
at _checkHoveringControls (kaltura-player-selector.js?ver=2.7:136)
at _onPlayerChange (kaltura-player-selector.js?ver=2.7:84)
at Object._onPlayersLoadedSuccess as success
at i (VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:2)
at Object.fireWith [as resolveWith] (VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:2)
at y (VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:4)
at XMLHttpRequest.c (VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:4)
_checkHoveringControls @ kaltura-player-selector.js?ver=2.7:136
_onPlayerChange @ kaltura-player-selector.js?ver=2.7:84
_onPlayersLoadedSuccess @ kaltura-player-selector.js?ver=2.7:54
i @ VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:2
fireWith @ VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:2
y @ VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:4
c @ VM1385 load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,utils,plupload,plupload-handlers&ver=…:4
mwEmbedLoader.php?&wid=104&uiconfid=23448265&p=104&iframeServer=true:50 kWidget: Kaltura HTML5 Version: 2.49 ( iframe )