He was not referring to the divisions we face today, which boils down to prophets vs scholars regarding the Hill Cumorah. Nevertheless, this division is definitely a stumbling block.
The division consists of these two opposite teachings:
1. The prophets have consistently and persistently taught that Cumorah (Moroni 6:6) is in New York.
2. The M2C intellectuals have consistently and persistently taught that Cumorah is not in New York and that the prophets are wrong. These M2C intellectuals have persuaded employees at BYU/CES and COB (the Church Office Building) to follow them instead of the prophets.
Hence, the division, which is a stumbling block to investigators (and members).
The damage caused by this stumbling block is evident all around us.
I say it's time to eliminate the division by accepting and publicizing the teachings of the prophets about the New York Cumorah. This means the M2C scholars will have to conform their teachings to what the prophets have taught, but they should have been doing this all along.
I don't think this is going to happen until the magnitude of the stumbling block created by the M2C scholars is so great that it is no longer tolerable.
*David Whitmer, An Address to All Believers in Christ, p. 4.