I was working on a Set Variable script step with a Let statement that sets a large number of variables. The script step had been copied from another script and had a number of errors to correct. I was interrupted in the middle so commented out the whole formula with /* */ so I could save my work and continue it later. When I opened the script step late the text had been compacted. See the attachement Collapsed.jpg. It should have looked like Correct.jpg.
I have seen this in earlier versions of FileMaker. It only seems to happen in script steps like this were there is a lot of text. I have done this with out having the issue with less text in the calculation and have been able to use /* */ with in a script step to comment out blocks of code.
This was done on a Mac Book Pro ( Retina mid 2012 ) running OS X 10.10.5 in FileMaker Pro Advanced 188.8.131.52.