Ambibuous code block

I've started getting an "Ambiguous code block" error on some of my code. I'm using InteliJ 2018.2 Weirdly, if I change some white space, the error goes away! The problem appears to only be occurring in some of my catch blocks.

This shows no errors or warnings:

catch(ParseException pe) {
   comment.datestamp = new Date();
}

Whereas this shows an Ambiguous code block error:

catch(ParseException pe)
{
   comment.datestamp = new Date();
}

A very similar problem is also this code which InteliJ claims has the continue in an invalid place:

catch(Exception e)
{
   ...
   counter++;
   continue;
}

But this is fine:

catch(Exception e) {
   ...
   counter++;
   continue;
}

In both these examples, if the gap between the ")" and the "{" isn't exactly 1 space, InteliJ shows an (invalid) error.