Literally, the first thing I did with Mathematica 12 was open up a documentation page, copy over the code to a notebook to run it, and discover that the highlighting on copied code is wrong.
The notebook on the right is Mathematica 12 and the one on the left is 11. No matter how many times you evaluate either of the cells in 12, volume stays blue...
But I'm sure it's much better in other respects, I need to use it more.
Seriously?!?! The second thing I did was type "OptionQ" into the documentation center and it crashed Mathematica. Not just the notebook, the whole thing.
@C.E. yeah between my undocumented usage and asking it to make me heavy duty graphics with tons of points or very large matrices etc. it likes to crash
Also sometimes I miss my brackets and type RandomReal[{}, RandomInteger[15, 25]] ;____;
And then my computer freezes as Mathematica tries to eat every piece of memory I have
well done Version 12 with DSolve. Mathematica 12 performed much better than Mathematica 11.3 both in the number of PDE's problems solved and in the speed it solved them. Link here 12000.org/my_notes/pde_in_CAS/pde_in_cas.htm Version 12 seems much faster than 11.3.
People on Windows: could someone test is Writeing to NUL actually creates a file called NUL or if it acts the same as /dev/null on Unix (i.e. output disappears)?
Bug introduced in 10.0 or earlier and fixed in 12.0
Note: Associations are new in 10.0
Here is a nice graph whose vertices are Associations:
g = Graph[{
<|"n" -> 1|> -> <|"n" -> 2|>,
<|"n" -> 1|> -> <|"n" -> 3|>,
<|"n" -> 2|> -> <|"n" -> 4|>,
<|"n" -> 3|> -> <|"n" -> 4|>},
Vert...
I had to copy that in two pieces: one halfway through the "\"\<\:d8 and then one resuming from 3d\>\"" since you can't copy a string containing one of these things either apparently.
@C.E. I've been seeing that since 11.0. Where sometimes, the symbols won't turn from blue to black. Can never reliably reproduce it, and hits me about every other week.
@user6014 @C.E. that's generally an issue for me right after a fresh kernel start. What fixes it (usually) is evaluating Internal`SymbolLists[True] and then Remove-ing the affected symbols and defining them again.
Basically the FE symbol tracking mechanism got confused and need to relearn its symbols
You can also force it to recognize them again using what's here
Bug introduced in 10.0 or earlier and fixed in 12.0
Note: Associations are new in 10.0
Here is a nice graph whose vertices are Associations:
g = Graph[{
<|"n" -> 1|> -> <|"n" -> 2|>,
<|"n" -> 1|> -> <|"n" -> 3|>,
<|"n" -> 2|> -> <|"n" -> 4|>,
<|"n" -> 3|> -> <|"n" -> 4|>},
Vert...
