Ubuntu – Pepper flash plugin is installed but doesn’t work on chromium

I installed aptitude and got these proposed solutions:

$ sudo aptitude install makerware
The following NEW packages will be installed:
  avrdude{a} conveyor{a} conveyor-common{a} conveyor-ui{a} libarmadillo4{a} 
  libarpack2{a} libboost-program-options1.54.0{a} libcoin80{a} libdap11{a} 
  libdapclient3{a} libdigitizer{a} libepsilon1{a} libfreexl1{a} libftdi1{a} 
  libgdal1h{a} libgeos-3.4.2{a} libgeos-c1{a} libgraphicsmagick3{a} 
  libhdf4-0-alt{a} libhdf5-7{a} libjsoncpp0{a} libkml0{a} libmbqtutils{a} 
  libmysqlclient18{a} libnetcdfc7{a} libogdi3.2{a} libopenmesh-3.2{a} 
  libopenscenegraph99{a} libopenthreads14{a} libpq5{a} libproj0{a} 
  libqt5multimedia5{ab} libqt5multimediawidgets5{a} libspatialite5{a} 
  libthing{a} libtinything{a} libtoolpathviz{a} liburiparser1{a} 
  libxerces-c3.1{a} libxine2{a} libxine2-bin{a} libxine2-doc{a} 
  libxine2-ffmpeg{a} libxine2-misc-plugins{a} libxine2-plugins{a} 
  makerbot-driver{a} makerware mb-libjsonrpc{a} mb-libopencv2.4{a} 
  mb-libstdc++6{a} mb-libvtk5.10{a} mb-pyserial{a} miracle-grue{a} 
  mysql-common{a} proj-bin{a} proj-data{a} 
0 packages upgraded, 56 newly installed, 0 to remove and 0 not upgraded.
Need to get 206 MB/206 MB of archives. After unpacking 340 MB will be used.
The following packages have unmet dependencies:
 libqt5multimedia5 : Depends: qtbase-abi-5-2-1 which is a virtual package.
The following actions will resolve these dependencies:

     Keep the following packages at their current version:
1)     libqt5multimedia5 [Not Installed]                  
2)     libqt5multimediawidgets5 [Not Installed]           
3)     makerware [Not Installed]                          



Accept this solution? [Y/n/q/?] n
The following actions will resolve these dependencies:

      Remove the following packages:                                            
1)      libqt5help5                                                             
2)      libqt5xmlpatterns5                                                      
3)      musescore                                                               
4)      qml-module-qtquick-localstorage                                         
5)      qml-module-qtquick-window2                                              
6)      qml-module-qtquick2                                                     
7)      qml-module-qtwebkit                                                     

      Install the following packages:                                           
8)      libqt5positioning5 [5.2.1-1ubuntu2 (now, trusty)]                       
9)      libqt5sensors5 [5.2.1+dfsg-2ubuntu2 (now, trusty)]                      

      Downgrade the following packages:                                         
10)     libqt5clucene5 [5.3.0-5~trusty1 (now, trusty) -> 5.2.1-8build1 (trusty)]
11)     libqt5core5a [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-1u
12)     libqt5dbus5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-1ub
13)     libqt5gui5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-1ubu
14)     libqt5network5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-
15)     libqt5opengl5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-1
16)     libqt5printsupport5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+
17)     libqt5qml5 [5.3.0-3ubuntu13~trusty1 (now, trusty) -> 5.2.1-3ubuntu15.1 (
18)     libqt5quick5 [5.3.0-3ubuntu13~trusty1 (now, trusty) -> 5.2.1-3ubuntu15.1
19)     libqt5sql5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-1ubu
20)     libqt5sql5-sqlite [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+df
21)     libqt5svg5 [5.3.0-2~trusty1 (now, trusty) -> 5.2.1-1 (trusty)]          
22)     libqt5test5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-1ub
23)     libqt5webkit5 [5.3.0+dfsg-1ubuntu2~trusty1 (now, trusty) -> 5.1.1-1ubunt
24)     libqt5webkit5-qmlwebkitplugin [5.3.0+dfsg-1ubuntu2~trusty1 (now, trusty)
25)     libqt5widgets5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-
26)     libqt5xml5 [5.3.0+dfsg-2ubuntu9~trusty1 (now, trusty) -> 5.2.1+dfsg-1ubu
27)     qtdeclarative5-localstorage-plugin [5.3.0-3ubuntu13~trusty1 (now, trusty
28)     qtdeclarative5-qtquick2-plugin [5.3.0-3ubuntu13~trusty1 (now, trusty) ->
29)     qtdeclarative5-window-plugin [5.3.0-3ubuntu13~trusty1 (now, trusty) -> 5



Accept this solution? [Y/n/q/?]

It seems that when I added the repository for MuseScore and upgraded MuseScore to 2.0, it also updated qt to 5.3 which seems to be incompatible with Makerware.

For now, it looks like I have to downgrade MuseScore or not use Makerware.

This is because KDE 5.7 hasn't been backported to Kubuntu and added to the backports ppa yet.

I've been waiting too, so I hope someone involved in the project will comment on when they expect that to be done.

Edit: I notice that you actually on KDE 5.5.5. You should at least get upgraded to 5.6.5, which is available for Kubuntu 16.04. Try running kinfocenter to double check your version information.

Update: It doesn't like like KDE Plasma 5.7 will be available for 16.04 at all, I think you will have to upgrade to 16.10 next month or switch to the Neon distribution.