I think it's scripting errors flags.

These are the symbols for corrupted or wrongly uploaded meshes. Often seen after clearing the cache when importing mesh files too.

The pyramid symbols are for mesh loading errors. i think they go away after the mesh is fully loaded. Script errors are different - they are a yellow triangle with a question mark.

yep scripts errors you get this when you dont remove the lsl scripts before you (DARK-STORM) somthing from second life.also if you have too many of these it will cause you serious lag issues on your region and if you run a grid and a few people have these then your grid will have very bad issues.also if the textures are brought over wrong you will infect your grid with corrupted texture coding errors (NOT GOOD) for your grid.

Although I have not seen those in quite a while, I remember them enough to know that I had that exact same question years ago, and I just went with they were script errors. I hope someone else can give a more definitive answer than mine. :)

U might fix it by cleaning manually the cache as I`ve seen at : https://community.secondlife.com/forum...

LSL scripts warnings symbol
If you interested - google this phrase