Q: If someone changes things in a commercial lease, with white out, post signing it, is that a breach of contract?

A: I don't think there are enough facts in your question to be able to give any response It doesn't say whether you took a copy of the signed, unaltered lease with you at the time you and the landlord signed it; or whether you told the landlord that the lease had been changed when you "went to get" the lease; or what the landlord said to you (and what you said to the landlord) about the white out when you pointed it out to him (if you did); or whether the landlord showed you a photocopy of the original lease so that what was whited out was not obvious (and in which case the signatures would have been photocopies, not originals); or whether the landlord gave you a copy of the altered lease; or what was changed by the white out; or what the landlord said to you about the $4,000; or the date the lease was signed (whether before or after the Governor's first shut-down order in early March 2020); or the dates in the lease for the term and rent to begin and the date you went to get the lease; or whether the lease included a "force majeure" clause; or whether the lease had a deadline for something to be done which affected whether the $4,000 was refundable or not; or whether the lease had a "time is of the essence" provision in it generally or one specifically about the $4,000. At the least, expanding your question to include all the above information would improve a lawyer's chances of providing you with a useful response.