Regression Learner App taking too long to return models

Hi! i'm running into a bit of trouble with my Matlab while processing some data - I have three columns of variables (18041 rows each) and one column for answer; I'm trying to run diverse regression models for them.

Here I have my set of variables and my answer (Ie_Mittal); I've been able to run some models smoothly and pretty quickly, such as regression trees and linear regressions - however, for models such as Gaussian Processes or SVM, the program doesn't seem to be able to finnish running it -

It keeps on training it forever, coming to a point where I left it to run overnight and after about 12 hours it still hadn't come to an answer. Trying to stop it is also no good - I have to end the whole program via task manager.

Weirdly enough, although my computer isn't so good, I have been able to run gaussian processes and svm smoothly before with a very similar set of data (and a even bigger one at that), so I'm not too sure what I might be doing wrong. I tried changing PCA and cross-validation data around, re-installing the program and the tool box etc etc, and I wasn't able to come to an answer.

Any help will be very much appreciated, and I can show more info on my problem as asked!