When the last two updates were issued the phpBB designers listened to the needs and wants of the users, so certain image formats were dropped in favor of a more mobile friendly format, .svg
There is no certain method to convert any image format to .svg, the only thing that sort of conversion does is wrap it, which means it is still whatever original format with none of the advantages of svg
Until I make another image file using the svg format, there won't be a site logo displayed on this message board. No telling when that might be, as I've very little experience with vector drawing. I need to learn first. Then make the logo image. So yeah, don't hold your breath. I will get it done, but no promises of when.
Thanks.
WR Admin