First next time please google error message. 95% of the time any problem or error message from any program can be solved simply by googling the error message. With PC's most of the time the exact error you are having has already been found by someone else and they have done the same as you and asked for help. So always consult the all mighty google before making a post anywhere you visit.
EDIT :
Open any char .def file using notepad. it comes stock with all version of windows. Anyways Quote from Mugen Guild forum mugen FAQ :
If you get the dreaded "assert failure in charsel.c line 3162"
To dumb it down a little, you have to check everyone one of your character's .def file to see if it's missing a line of code. Listen carefully:
1. Suppose the character's name you are checking is called "supernoob."
2. Every character has a .def file.
3. A .def file is like a ID/driver license
4. And let's say that the .def file name is supernoob.def
5. open your character's folder
6. Look for supernoob.def. open it.
7. You should get something like this:
; Player information
[Info]
name = "Supernoob"
displayname = "Supernoob"
versiondate = 07,17,2000
mugenversion = 06,27,2000
author = "Black-Baster"
8.
; Player information
[Info]
name = "Supernoob"
displayname = "Supernoob"
versiondate = 07,17,2000
mugenversion = 06,27,2000
author = "Black-Baster"
pal.defaults = 1,3,4,6 <=== (If this character "supernoob" already has a line of pal.defaults code, then this one is good. Go check another character, and repeat the whole process again from 1. to 8. If this character doesn't have a code like that, then goto 9.)
9.
; Player information
[Info]
name = "Supernoob"
displayname = "Supernoob"
versiondate = 07,17,2000
mugenversion = 06,27,2000
author = "Black-Baster"
pal.defaults = 1,2 <=== (Add this line of code here if there isn't already a pal.defaults code )
9. save supernoob.def and close it.
10. Keep checking and adding pal.default codes as necessary until everyone of your characters in your MUGEN game is taken care off.
11. Run your mugen game and see if the same problem comes up.
FAQ link if you have anymore problems :
http://mugenguild.com/forumx/index.php?topic=37273.5;wap2Again with all error messages for any program on a PC please consult google before making a post. You will save yourself
of time. Sometimes people can not respond in a timely manor so even after you have posted asking for help you should scour google looking for information.
But I hope this helps.