As usual, Rainmeter 4.5 is fully backwards compatible with skins written for any version of Rainmeter
You need only install on top of your existing installation.
No need to uninstall 4.4 or worry about overwriting changes you have made.
Also, can you identify the skin that is causing the issue? Start by unloading all the skins that are running when the issue happens. Then you can load them 1 by 1 until the issue happens. Then post that skin here, along with any external files needed to run the skin like images, scripts, etc.
It was from the "backlight plugin" not from the app itself, if I use the UpdateDivider=1 will keep crashing, it has to be -1
I think there's an issue with that plugin