I'm also stuck with FSR error when using DT's elapsed timer on 16F1936

No MIBAM this time :)

I tried to use original files, but they got that error, then I found this post:

https://www.picbasic.co.uk/forum/sho...=elapsed+timer

tried code from it, but it won't compile, since 16F1936 does not have Timer 3, it has timer 1-2-4-6.

So as I understand, I should modify that code and change all references to timer3 to another timer. But which one to choose?

why timer3 ?
any timer that can provide a 10mS interrupt could be employed, the self configuring aspect of the code will not function for modern pic chips. the code will need a tickle to adapt it to valid timer settings for your chosen chip
what have you tried ?