"Our plan to destroy Dagoth Ur also runs the risk of destroying the Tribunal. The plan is to permanently disrupt Kagrenac's enchantments upon the Heart, severing connections with Dagoth Ur and ourselves, and rendering us all once again mortal. A mortal Kagrenac may then be destroyed by mundane means. The loss of godhood and the possible death of the Tribunal are judged a necessary risk and sacrifice."
I think most people, including myself, upon being made aware of this disregarded it as a typo. Having recently re-read the 36 Lessons of Vivec, however, I think the issue might be worth further exploration.
I observe that in http://www.imperial-library.info/mwbooks/dagoth_plan.shtml, the first point in the section "Objectives," contains a parenthetical note:
"Dagoth Ur has apparently adopted the views and motivations of the Dwemer High Craftlord Kagrenac. In effect, he recapitulates the ancient blasphemous folly of the Dwemer."
Here Vivec Clearly draws a parallel between Dagoth Ur and Kagrenac. What is striking, to me, is how specious this parallel seems to be. From what we know of their respective projects, Kagrenac's plans for the Heart and Numidium were very different from Dagoth Ur's plans for the Heart and Akulakhan. According to the recieved accounts, Dagoth Ur claimed that Kagrenac was building Numidium as a weapon against the Chimer. It is possible that upon preparing the document Vivec still believed Dagoth Ur's account of Kagrenac's intentions, but it seems strange that Vivec would continue to believe the one whom he explicitly calls a deciever. Of course, I do not think Vivec ever managed to really understand the Dwemer, or Kagrenac.
Finally, I turn to the 36 Lessons of Vivec. I have long thought that the 3 Lessons for Ruling Kings, and other related sections, have (at least) two layers of meaning. On the one hand they are about Vivec's interactions with Indoril Nerevar - though most likely a highly edited account so as to make Vivec appear the wise teacher, and Nerevar the eager but foolhardy apprentice. On the other hand, they are messages, advise, and instructions to the Nerevarine.
In contrast, I had always, without much effort at justification, read the sections about the Sharmat as a reference to Dagoth Ur only. However, I am now tempted to think there might be something in reading the relevant sections (specifically sermons http://www.imperial-library.info/mwbooks/lessons.shtml#11, http://www.imperial-library.info/mwbooks/lessons.shtml#13, http://www.imperial-library.info/mwbooks/lessons.shtml#15, http://www.imperial-library.info/mwbooks/lessons.shtml#17, and http://www.imperial-library.info/mwbooks/lessons.shtml#36) in a similar way as I had read the others: as being abou both Dagoth Ur and Kagrenac, only on two different levels. (I seem to recall that the Sharmat has been linked to Kagrenac before, but I cannot remember who suggested it.)
Notice that in sermon 36 Vivec refers to "Kagrenac the Blighter" - clearly drawing a parallel between Kagrenac and Dagoth Ur. Later another passage links the blight to the Dwemer: "Resdaynia was no more. It had been redeemed of all the iniquities of the foolish. The ALMSIVI drew nets from the Beginning Place and captured the ash of Red Mountain, which they knew was the Blight of the Dwemer and that would serve only to infect the whole of the middle world, and ate it. ALTADOON DUNMERI!"
In the same sermon, we find the line "Red Mountain exploded as the Hortator went too far inside, seeking the Sharmat," is immediately followed by "Dwemeri high priest Kagrenac then revealed that which he had built in the image of Vivec. It was a walking star, which burnt the armies of the Triune and destroyed the heartland of Veloth, creating the Inner Sea." Recieved accounts of the event confirm that Nerevar went into Red Mountain in search of Dagoth Ur, which is consistent with interpreting Sharmat as refering to Dagoth. Yet the fact that Kagrenac appears in the next line is highly suggestive - as if Nerevar went looking for Dagoth and found Kagrenac.
This suggests to me that the line in Plan to Defeat Dagoth Ur is not to be disregarded as a typo. It seems that Vivec concieves of Kagrenac and Dagoth Ur as very similar, if not parallel figures. However diverse their characters may be, as far as Vivec is concerned they play the same metaphorical-mythical role. Both are the Sharmat.