Find/change GREP not working now

Hi.  I have been using a GREP in the Find/Change dialogue for almost a year and it has worked perfectly.  I work with video scripts and I have to find and remove timestamps (ex. 00:01:53).  I've been using the GREP: [0-9][0-9]:[0-9][0-9]:[0-9][0-9]  or this one has also worked as well: \[[0-9][0-9]:[0-9][0-9]:[0-9][0-9]]

However, now it's not working when I have "Document" selected in the drop down menu (It says "Cannot Find Match").  It only works when I select the text and select "Selection" in the drop-down menu.  And even then, it will only work on a short selection.  If I select text on too many pages (that's flowing through them), it just will say "Cannot Find Match".

Here's what I've tried so far that has NOT WORKED:

• Deleted all the InDesign preferences
• Uninstalled and reinstalled InDesign (without saving preferences)
• Created a new document and input the text (just on page 1) and tried searching it then
• Downloaded the original text in different formats (i.e. Word, Rich text, simple text, etc.)
• Tried selecting all the special buttons under the drop-down in the Find/Change dialogue box
• Tried searching with "Story" selected in the drop-down menu
• Note: There's nothing in my Find Format area or my Change Format area

So far, nothing I have tried is working and there is no way for me to get rid of these timestamps and I have hundreds of pages of them.  So, one-by-one will take forever.