The error is pretty clear: "initial decelerations are only allowed in C99 and onward"
so in your code you have something like this:
for(int i = 0; i < 3;++i)
prior to the C99 standard it was not allowed do declare your variable in the for loop header.
To fix this you can use the following code:
int i = 0;
for(i= 0;i< 3;++i)
or you compile with c99 enabled:
Project->Build options
make sure you have selected the top most entry in the tree control on the left
Compiler settings->Compiler flags-> Make a tick at "Have gcc follow the 1999 ISO C lang......" -> OK
rebuild your project by
Build->Rebuild
greetings