I've had this issue too with some older anime i'm watching.
I tried MAG79's suggestion, but i couldn't get subtitles to display.
My workaround: (Make a backup of your SVP files first, as i cannot be held responsible if doing the below creates a rip in spacetime)
1) Download the latest TIVTC from https://github.com/pinterf/TIVTC/releases
2) Extract TIVTC.dll from the x64 folder into C:\Program Files (x86)\AviSynth+\plugins64+
3) Copy your generate.js file in C:\Program Files (x86)\SVP 4\script to somewhere like My Documents where you can edit it without admin privileges. (I also made a generate.js.old at this point)
4) Open the copied generate.js in notepad
5) There are 2 sections that need to be changed.
if(profile.fi_duplicates===1)
{
AVS.push("SelectEvery(2,0)");
AVS.push("");
}Change the "SelectEvery(2,0)" to "TDecimate(cycle=5)" (including the quote marks)
if(profile.fi_duplicates===1)
VS.push("clip = core.std.SelectEvery(video_in,2,0)");
else VS.push('clip = video_in');Change the SelectEvery(video_in,2,0) to TDecimate(cycle=5)
6) Save the file
7) Now copy the modified generate.js into C:\Program Files (x86)\SVP 4\script, saying yes to overwrite.
8) In the SVP GUI, with your desired profile, Scroll down to Duplicate Frames Removal and Select "Remove every other frame"
9) Congrats. You now have 5th frame removal and working subtitles.