Answer:
Here's wat always works for me..
Up where it says what site ur in (a long bar), shud be a tiny lock. if u click that, u will see an option that says site settings. click that. it will take u to a page called settings. look for the option that says flash. on the left side shud be a tiny triangle where u can choose whether it is blocked or allowed. click allow. then u can x that page, but reload the page ur working on by clicking a blue reload button that shud come up. there u are, good as new!!
hoped this helped!! if u have questions, feel free to ask (even tho it mite take a while for me to answer sometimes..)
have a beautiful rest of ur day!!