On fresh install - i got this error :
"Fatal error: Class 'rsgInstance' not found in ....\administrator\components\com_rsgallery2\includes\config.class.php on line 193"
The installation finished though.. and i could start adding photos. From the short time i used it, i could not see any misbehaviour.
I tried uninstall , and a new installation (of RSgallery2) , and got the same error message , but less information of installation progress : Only 2 off :
"Menu Image RSGallery2 succesfully changed" / "Migrating from RSGallery2 1.14.0"

cheers
Frank

SVN 436 gave me the same error , but reference the error as :
"Fatal error: Class 'rsgInstance' not found in ...\administrator\components\com_rsgallery2\includes\config.class.php on line 197"

I did not open the referenced class / source, to compare what was the difference.
The latest install [SVN 445] did not give me this error

.. but instead i experianced the same as in the thread : http://rsgallery2.net/component/option,com_smf/Itemid,17/topic,8732.0

oh well.. The developers are busy.. and they are movong forward <g>
Frank