In that case, you’d typically need to file a legal challenge, which could involve going to court and showing that the restriction is unnecessary or unreasonable.The best advice I can give would be to consult a real estate attorney to understand your specific situation and options.

You can tell the tenant that they can ignore the notice as long as they follow through on paying.As the landlord you want to maintain control of the situation - not allow the tenant to do so.

I wanted to share my situation and get some advice.I currently own an apartment in a highly developing area in Guaynabo, PR.

I don't know your living situation but if your paying x,xxx for rent or a mortgage and instead by living in one side and renting out the other you will be paying y,yyy instead and y is less then x that's great, especially if you can rent out your primary residence and make income there too. 

Obviously tough to give advice based on minimal info and no info on your personal situation.

It sounds like you've absorbed a bunch of problems already and a new sewer line and the current basement situation will cost you way less than the $50K in fees to sell it. 

Is this something you have done multiple times?

I use credit cards, write checks, and pay in cash.Each situation can dictate the payment type. 

When speaking with them, demonstrate genuine interest in their situation and goals.

But it feels like if you keep cashing out equity on your properties to buy another, you end up with multiple properties but with your equity stretched really thin, like a house of cards ready to collapse.