http://www.mapleprimes.com/questions/126081-Hi-I-Have-The-Same-Problem en-us 2026 Maplesoft, A Division of Waterloo Maple Inc. Maplesoft Document System Wed, 10 Jun 2026 21:25:48 GMT Wed, 10 Jun 2026 21:25:48 GMT The latest answers and comments added to the Question, Hi! I have the same problem. http://www.mapleprimes.com/images/mapleprimeswhite.jpg http://www.mapleprimes.com/questions/126081-Hi-I-Have-The-Same-Problem http://www.mapleprimes.com/questions/126081-Hi-I-Have-The-Same-Problem?ref=Feed:MaplePrimes:Hi! I have the same problem.:Comments#answer127076 <p>I looked at the model (tdk7.msim) , which as you suggested, is rather complicated.&nbsp; It appears as there is a more fundamental problem than the event iteration.&nbsp; I temporarily prevented that message from occuring by forcing the boolean input to S4 (selector on middle-left) to be constantly true. With that we get the error message "index-1 and derivative evaluation failure on event at t=40.540882".&nbsp; The cause of that is that the "denominator" to divider D5 (left side of schematic) is going to zero.&nbsp; Note that its output is from switch S2, one of whose inputs is tied to 0.&nbsp; You need to figure out how to prevent a division by zero.&nbsp; I don't know what the model is doing to suggest something.</p> <p>I looked at the model (tdk7.msim) , which as you suggested, is rather complicated.&nbsp; It appears as there is a more fundamental problem than the event iteration.&nbsp; I temporarily prevented that message from occuring by forcing the boolean input to S4 (selector on middle-left) to be constantly true. With that we get the error message "index-1 and derivative evaluation failure on event at t=40.540882".&nbsp; The cause of that is that the "denominator" to divider D5 (left side of schematic) is going to zero.&nbsp; Note that its output is from switch S2, one of whose inputs is tied to 0.&nbsp; You need to figure out how to prevent a division by zero.&nbsp; I don't know what the model is doing to suggest something.</p> 127076 Wed, 26 Oct 2011 21:30:17 Z Joe Riel Joe Riel