Keep in mind, i know very little about computers, so if there is a solution, explain it like you're trying to teach someones great grandmother...
Sorry for the delay in response.
Please try once to repair the installation. If you are on Windows, launch the application and go to Help menu at the top.
Then select "Repair Installation" from the drop down list.
Check if you still experience the same issue.
If you still experience the issue, please elaborate what exactly you mean by "Page now blinks repeatedly" here?
Do you mean to say that the page freezes and then works after some time? Or you referring to some other behavior?
Is it an issue with all the PDF's? Try to check with other PDF's.
Let us know if you need any help.