Starting with version 188.8.131.52 BinTube Ultimate uses the Chromium web browser which doesn't provide built-in Adobe Flash support. To enable Flash you need to download the PPAPI version of Flash from https://get.adobe.com/flashplayer/otherversions/
After choosing your Operating System select the "FP XX for Opera and Chromium - PPAPI" version and click Download Now.
Then execute the downloaded program which will install Flash and optionally keep it updated on your system.
The next time you start BinTube Ultimate, Flash should be working.