Terje, to fix
the below plugin errors, you will have to modify
cinelerra-5.1/ffmpeg/plugin.opts for your specific ffmpeg
version since it will be different from everyone else when
using your O/S version. Since you have successfully completed
the build, you can just modify
cinelerra-5.1/bin/ffmpeg/plugin.opts instead. This file is a
blacklist and it is self-explanatory when you look at the last
few lines of the file. Just add # lines for each of the error
plugins. For example, add: #lv2 and #sofalizer, etc.