Check if DynDOLOD\Edit Scripts\Export\LODGen_SSE_Tamriel.txt contains a line like
xxxxxxxx 00000000 -55314.347656 100706.976563 -8728.261719 0.0000 0.0000 135.0000 1.0 DBM_MuseumBuilding 00000000 -LargeRef meshes\dbm resources\architecture\museum.nif meshes\lod\dbm\museum_lod.nif meshes\lod\dbm\museum_lod_1.nif meshes\lod\dbm\museum_lod_2.nif
If not, then DynDOLOD Resources Core Files might not be fully installed, like an incomplete download or the archive was not fully extracted. Check the installed DynDOLOD Resources Core Files have meshes\lod\dbm\museum_lod.nif
If that seems fine check if DynDOLOD\Logs\LODGen_SSE_Tamriel_log.txt last line is Code: 0
The DynDOLOD\Logs\DynDOLOD_SSE_log.txt should have LODGenx64.exe for Tamriel completed successfully near the end.
If all that seems fine, make sure that all files from output folder are installed and none are overwritten by other mods.