URGENT need support for broken wordpress sites

Some of my sites in my network have all of a sudden started showing just white screens while some are totally fine. I have no idea what is going on but have narrowed down part of the problem to the visual composer plugin because if I rename the subfolder to something else some sites start to work again - yet some sites are still showing white screens. Also some broken sites I can access their backends yet some broken sites I can't access their backend... I have tried everything and exhausted my knowledge of what may be going on and my clients are starting to get upset.
Does WPMUDEV provide support for this? If not I would certainly pay extra for this. This has become an urgent issue for me and I need someone knowledgeable to look into this for me and get this resolved. Again I am willing to pay. If you do not provide this type of support can you at least point me to some reputable companies that do.
Much appreciated and thanks in advance!