Opening htm file in workbench MII v 14 SP5

when I open a htm file in workbench I get a popup that says Error - NULL

java.lang.StackOverflowError
 at java.lang.Character.codePointAt(Unknown Source)
 at java.util.regex.Pattern$CharProperty.match(Unknown Source)
 at java.util.regex.Pattern$Branch.match(Unknown Source)
 at java.util.regex.Pattern$GroupHead.match(Unknown Source)
 at java.util.regex.Pattern$Loop.match(Unknown Source)
 at java.util.regex.Pattern$GroupTail.match(Unknown Source)
I deleted some of the 1000+ rows... but you get the idea...
 at java.util.regex.Pattern$BranchConn.match(Unknown Source)
 at java.util.regex.Pattern$CharProperty.match(Unknown Source)
 at java.util.regex.Pattern$Branch.match(Unknown Source)
 at java.util.regex.Pattern$GroupHead.match(Unknown Source)
 at java.util.regex.Pattern$Loop.match(Unknown Source)
 at java.util.regex.Pattern$GroupTail.match(Unknown Source)
 at java.util.regex.Pattern$BranchConn.match(Unknown Source)
 at java.util.regex.Pattern$CharProperty.match(Unknown Source)
 at java.util.regex.Pattern$Branch.match(Unknown Source)
 at java.util.regex.Pattern$GroupHead.match(Unknown Source)

And it then shows a blank page

I can right click on the file in the tree and choose open and will be able to see the text on the page.

Unfortunately then the file will not save...