See this (didn't test your RegExp, so it might work too):and compare the differences to understand it.
Code:
[Rainmeter]Update=1000AccurateText=1DynamicWindowSize=1[MeasureSite]Measure=WebParserURL=https://www.shotcutapp.com/download/RegExp=(?siU)<h4 id="current-version-.*">Current Version: (.*)<\/h4>UpdateRate=3600[mfirstchild]Measure=WebParserURL=[MeasureSite]StringIndex=1[MeterDummy]Meter=StringFontColor=180,180,180SolidColor=150,0,0FontSize=14Text=Version : [mfirstchild]LeftMouseUpAction=[!Refresh]DynamicVariables=1Statistics: Posted by Yincognito — 2 minutes ago