Fietspomp the latest projectM Add-on (version 20.2.0.1) supplied by Team Kodi should work without issue on Generic-legacy LibreELEC-Generic-legacy.x86_64-11.0.3
If you are running one of the newer Libreelec 12.x Nightly builds, there is a good chance that the proejctM add-on is not yet compatible.
chewitt Thank you! After clearing the add-on cache and then rebooting, I was able to install the Shadertoy add-on which is now working without issue on LibreELEC (Nexus) 11 Beta2 (Generic-legacy build).
heitbaum I don't yet see the ProjectM add-on available (within Look and feel > Visualization) - but will keep checking periodically.
Possibly related: Note that after installing LibreELEC (Nexus) 11 Beta2 (Generic-legacy build), the Shadertoy add-on seems to be reliant on libGLESv2.so.2:
error <general>: Unable to load /storage/.kodi/addons/visualization.shadertoy/visualization.shadertoy.so.20.3.0, reason: libGLESv2.so.2: cannot open shared object file: No such file or directory
chewitt - I installed LibreELEC (Nexus) 11 Beta2 (Generic-legacy build) and ProjectM is unfortunately also unavailable,
Goom: Not certain if you meant ShaderToy (which is available for both the LibreELEC (Nexus) 11 Beta2 Generic and Generic-legacy builds) but Goom is a fairly simplistic visualization that does not currently support the wide variety of user generated visualization presets.
Thankfully, I was able to downgrade back to LibreELEC 10.0.4 (Generic build) without too much trouble in order to get the ProjectM add-on back.
Is there an ETA for ProjectM add-on availability for LibreELEC (Nexus) 11 Beta2 (Generic build)?
It looks like ProjectM version 20.2.0-Nexus has been available since 16 September 2022 (https://github.com/xbmc/visualiza…ag/20.2.0-Nexus) but when upgrading from LibreELEC 10 to LibreELEC 11 Beta 2, the ProjectM add-on was removed as being incompatible with no replacement currently available. 
Thanks in advance!
