They must provide the tenant a certain amount of time to remedy the current situation (in this case, payment of two months rent) within a certain time period (3 Days).  

Without that, the remedy (if allowed) would be a judicial foreclosure (think more time and more money).

Any one know what this could be and how to remedy?

For all these reasons  @Rocky V. sub too in the wrong hands are about as dangerous a thing you can do.what you needed to do was a wrap with a notice of default provision in that you would have all the contact info and your 3p authorization up front before you closed so you couild remedy this.you will need to refi and pay bank off is what you will need to do.. or come up with cash or find a JV partner that will provide the KISH to take care of this.its usually the sellers that get screwed in these deals but buyers can too.. in the exact manner that is happening to you

Remediation?

Remedy what you have to now and get your problem tenant gone.

Move on, keep your friends, never rent to family/friends again, and fix the lease agreement for the next one.For the upstairs/downstairs heat differential, that is often easily remedied by turning the central air fan on full time or if it has a circ option, use that.  

(The first thing that occurs to me is an "herbal" dispensary, but that's just because I have an unusual sense of humor.) 

If you are specifically looking for GCs that work with mold remediation, I would post on the forums with exactly what you are looking for. 

Is that my legal responsibility to remediate this problem?