Lauch 4J Error on Arduino IDE

If your Arduino IDE is slow and when it starts up it appears the Launch4j error, as shown in the below picture: 


Then follow this guide to fix the issue. 
This is a Java problem due probably to conflicting libraries.
"Delete or rename the existing Arduino data folder, normally it is placed in Documents, start up the Arduino IDE and Click OK if it asks you "to create a new Arduino folder". Now it should work and you can just reuse the old sketches saving them in this new arduino folder."