What happens when you are on notice of a will, but it is unprobated? One is supposed to probate a will right away, and many folks don't do it. If the will leaves the property to the same people that would inherit under the laws of intestacy our job is easier and we don't have to worry about it as much. It is when the devisees under the will and the heirs at law differ that we start having issues.
In Texas, a will can be probated any time within 4 years, and once admitted to probate the devisees of the will are vested in the bequest as of the date of death, subject to the Executor's authority to sell the property to satisfy debts of the estate, etc (therefore, a deed from the appointed executor trumps the devisee in the will). Therefore, any conveyance by the heirs at law during the 4 year period after death is subject to being zapped by the devisees under the will if it is admitted to probate. Therefore, any conveyance or lease of property subject to such an unprobated will should include the signatures of every heir at law, as well as every devisee under the will, in order to acquire everyone's potential interest.
A will can still be probated after the 4 year period as a muniment of title, the difference being that any probate after the 4 year period will not zap any title granted by the heirs at law. So, after 4 years title from the heirs at law is generally safer, and it is still wise to check to confirm that the will was not probated yet.