The logic for adding the 2.1 Alienine & Fugue smiley sets to smf_settings is failing. I believe Fugue is failing because it's the default, and there is already a default. Alienine is failing because of syntax. Note the directories are all there in the filesystem, but the names are confused because the smf_settings values are confused:

The logic for updating these values in the upgrader needs to be fixed.
Another problem: In 2.0, the default was alienine, so in the /default folder are alienine .gifs. In 2.1, the default is fugue, so in the /default folder are fugue .pngs. As a result, when installing the 2.1 files on top of the 2.0 files, you now get a mix of alienine & fugue in the /default folder. I suggest leaving the default at alienine, so the /default folder would include alienine .gifs & .pngs post installation.
Another consideration... Some folks may want to just delete the Smileys folder prior to upgrading. If this were to happen, the old 2.0 values in the settings table would point to missing folders & smileys. It might be helpful to confirm they exist. (We did this with themes, over here: https://github.com/SimpleMachines/SMF2.1/pull/3964/files)
This issue was split from #4767 .
The logic for adding the 2.1 Alienine & Fugue smiley sets to smf_settings is failing. I believe Fugue is failing because it's the default, and there is already a default. Alienine is failing because of syntax. Note the directories are all there in the filesystem, but the names are confused because the smf_settings values are confused:

The logic for updating these values in the upgrader needs to be fixed.
Another problem: In 2.0, the default was alienine, so in the /default folder are alienine .gifs. In 2.1, the default is fugue, so in the /default folder are fugue .pngs. As a result, when installing the 2.1 files on top of the 2.0 files, you now get a mix of alienine & fugue in the /default folder. I suggest leaving the default at alienine, so the /default folder would include alienine .gifs & .pngs post installation.
Another consideration... Some folks may want to just delete the Smileys folder prior to upgrading. If this were to happen, the old 2.0 values in the settings table would point to missing folders & smileys. It might be helpful to confirm they exist. (We did this with themes, over here: https://github.com/SimpleMachines/SMF2.1/pull/3964/files)
This issue was split from #4767 .