Posted by Precise Simulation on
URL: http://forum.featool.com/Error-use-multiple-time-dependent-boundary-conditions-tp1750p1791.html

Thank you for reporting the issue, and sorry for the delayed reply due to the holiday break.

This specifically seems to be due to the expression parser erroneously removing the parenthesis around the "20*(t<300e-6)" expression. This issue will be fixed in the next update/release. In the meantime you can either modify the expression and add a "(...)^1" to prevent this, that is "20*(t<300e-6)^1". Or as you already have found out split the solving in several steps.