Standard indicators, custom indicators or bought from the market indicators?
If its the 3rd, then you have to login into your community account in Tools >> Options >> Community.
Otherwise, reinstall your MT platform.
where do i find market folder please
When I bought EA so I saw the Market folder -
You need to delete the files within Market folder. Then download them again and will work
May be it's enough just to open your indi form the indo folder in the editor an (re-)compile it again.