If you get a -9957 error when attempting to use the ARRAY TO LIST command, be sure that you do not have the List open in the List Editor in the Design Environment. Having the List open in the List Editor will cause a -9957 error to occur. This error can be caught in ON ERR CALL as well.
Note: Due to the new implementation of Choice Lists, compatibility for this command could not be fully maintained. Also, starting with version 6, we recommend that you use the command SAVE LIST to work with the hierarchical lists defined in the Design environment List Editor.