Avoid potential crash
Avoid potential crash

Helioviewer-Project/JHelioviewer-SWHV,Helioviewer-Project/JHelioviewer-SWHV,Helioviewer-Project/JHelioviewer-SWHV,Helioviewer-Project/JHelioviewer-SWHV,Helioviewer-Project/JHelioviewer-SWHV