Your information is too little to identify.
What emulator is it? Emulator on PSP and VITA PCs?
This section describes the emulator on a PC.
Do you meet the PC specs?
PPSSPP is the best for PSP. VITA is Vita3K.
Although Vita3K is still under development, it is unstable.
But VITA's high-performance emulator is actually an option.
Vita3K official release minimum required specifications
CPU: x64 CPU
GPU: GPU compatible with OpenGL 4.1
OS: Windows 7/8/10, Linux, all 64-bit
Visual C ++ Redistributable for Visual Studio 2015
DirectX End-User Runtime Web Installer
This is the minimum requirement and must be met.
And there are some titles that Vita3K doesn't support.
Vita3K official compatibility list
https://vita3k.org/compatibility.html?lang=en
If you are PPSSPP, check it yourself.
This is a high degree of completeness and is stable. There is also information.
If it is different, please post in this forum.
http://www.anime-sharing.com/forum/search.php?searchid=95469155