XAMPP Table doesn't exist in engine

Question

I'm using xampp and I dropped a unique key index from a table as follows:

set FOREIGN_KEY_CHECKS=0; 
alter table mytable drop index unique_index_name;  
set FOREIGN_KEY_CHECKS=1;

I set FOREIGN_KEY_CHECKS=0 as one of the columns in this key has a foreign key relation with another table.

I checked the logs of mysql: the table has missing foreign key indexes.

Everything was fine until I restarted mysql. When I try to query this table only I get an error of: Table 'myapp.mytable' doesn't exist in engine.

1. how can I recover the table with its data.

2. is this xampp issue only or I will have the same issue in my live server?