Here is the explanation from Microsoft on this error Description of the R6025 run-time error in Visual C++. As you can read there, there is nothing YOU can do.

You can only run the installer again and choose Repair to repair your installation because it is possible that uedit32.exe or one of the DLLs is corrupt (failure on harddisk for example). It's also possible that your RAM or another important computer part is defect, but this is improbable if UltraEdit is the only program which runs not correct.

You have not posted which version of UltraEdit you use. If you have installed the latest hotfix, make sure that you have extracted all files in the hotfix archive over the files in the program directory of UltraEdit. It is extremly important that the EXE and the DLL match.

If repairing or re-installation of UltraEdit does not help, try following:

• Copy %appdata%\IDMComp\UltraEdit\ into the address bar of Windows Explorer and hit RETURN.
  You now should see the content of this directory where by default all the user specific configuration files are stored for UltraEdit.
• Close any instance of UltraEdit. Rename uedit32.ini for example to uedit32_bak.ini.
• Start UltraEdit. It will create a new uedit32.ini with default settings.
• Verify if the problem still exists or if it is gone.
• If the problem does not occur anymore, pack uedit32_bak.ini with ZIP and send it with an email with a detailed description what you do to see the error to IDM support. Hopefully IDM can reproduce the problem and the developers can look into it and fix this problem. In the meantime contiue with the default uedit32.ini and reconfigure UltraEdit to your needs.
• If the problem occurs also with the default settings, you can only contact IDM support by email and ask for help. But I think, then the problem is your computer hardware and you need to completely check it.