So, does the error also occurs when you are just using SQM3 and/or SQM4?
Does it also occur when you use numeric evaluation?
I see that you are using M040 which, according to the Readme of M050 suffers from the "issue with Mathcad 15.0 M040 in handling matrices with 256 or more elements"
There is no more information about this bug and so we can't say if its an issue which occurs from time to time in specific situations or if its something which is reproducible.
I also can't say if your installation of Mathcad got broken somehow and a reinstallation would help or if its a bug immanent to M040.
I attach the Readme of M050 so you can see which bugs were fixed since M040 (there were releases M045 and M050).
If you think its worth the trouble you may try to find the installation files for M050 somewhere on the net and upgrade your installation. The license for M040 should be valid for M050 as well. Of course you have to take care to save the license file!
BTW, the screenshot which shows the same error using my sheet - were you using my sheet unchanged? According to the error message the error occurs in line 258, position 9, which, if I am not wrong, is just after the definition (not evaluation) of SQM3.
No idea what would cause an error at this position.
