I keep bumping into this error, I have no idea what may be causing it, in a statistics book with lots of math: registered function call [250]: ...mtx/tex/texmf-context/tex/context/base/mkxl/lxml-mms.lmt:749: attempt to index a nil value (local 'a2') I have checked everything. I have tried commenting out many things and the weird part is that it fails in a simple math expression: \math{E_{i}j}. Even a simple $y$ or \math{a+b} will trigger the error. However, this same file Im working on has many formulas before that, those work fine. I changed all the $...$ to \math{...} just in case, but with no success. Already tried remaking, regenerating, updating the distribution. Do you have any ideas to work this out? I don't know how to provide a MWE for this because it's a very big project (statistics book). I have tried 2 versions, the system-wide one, just upgraded: mtx-context | ConTeXt Process Management 1.06 mtx-context | current version: 2024.02.22 18:31 And a less recent version, attached to the project: mtx-context | ConTeXt Process Management 1.05 mtx-context | current version: 2024.02.14 13:38 Any help will be much appreciated. -- Andrés Conrado Montoya Andi Kú andresconrado@gmail.com http://sesentaycuatro.com http://messier87.com http://chiquitico.org ---------------------------------------- Los fines no justifican los medios, porque la medida verdadera de nuestro carácter está dada por los medios que estamos dispuestos a utilizar, no por los fines que proclamamos. ---------------------------------------- “You develop an instant global consciousness, a people orientation, an intense dissatisfaction with the state of the world, and a compulsion to do something about it. From out there on the moon, international politics look so petty. You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, ‘Look at that, you son of a bitch.’” — Apollo 14 astronaut Edgar Mitchell