“Cbuf_InsertText overflowed” error means, that one of your script files exceeds the max allowed character limit.
When “Cbuf_InsertText overflowed” occurs, you have a few options to do:
1. Try to clead up your script file (in most of cases this script is your .cfg file and might contain lots of additional comment lines, you can get rid of)
2. Or try to split your script file in two or more smaller file and load them in your ET game separately.
The max script/cfg size is ~16kB. If your file exceeds this, it won’t be executed.