Issues in chat plus

I have error in chat plus, i cant send videos and dont see my users in it 

from conslole:

Firefox can’t establish a connection to the server at wss://chat.avren.co.il/sockjs/371/xn312zoy/websocket. bff2e10a5569d404d4da918ece78ebdbfa2393df.js:55:17964

Exception in template helper: footer@https://chat.avren.co.ilen.co.il/bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:79:14789 f._materializeDOM@https://chat.avren.co.il/bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:79:14825 t@https://chat.avren.co.il/bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:79:21129 e.nonreactive@https://chat.avren.co.il/bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:31:4396 t@https://chat.avren.co.il//bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:31:2311 e.Computation.prototype._recompute@https://chat.avren.co.il/bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:31:2538 e._runFlush@https://chat.avren.co.il/bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:31:3702 e@https://chat.avren.co.il/bff2e10a5569d404d4da918ece78ebdbfa2393df.js?meteor_js_resource=true:1:2198 bff2e10a5569d404d4da918ece78ebdbfa2393df.js:1:5928

Exception from Tracker recompute function: undefined bff2e10a5569d404d4da918ece78ebdbfa2393df.js:1:5998

Error: {{#each}} currently only accepts arrays, cursors or falsey values. undefined