An independent investigation has found police responding to concerns for a vulnerable woman who was later found dead were sent to the wrong house.
The daughter of a 52-year-old Dumfries woman raised safety fears about her mother with police in February 2016.
However, an issue between mapping and command and control systems meant officers went to the wrong address.
It took more than four-and-a-half hours to realise the error and the woman was then found dead at the correct address.
Police Investigations and Review Commissioner (PIRC) Kate Frame identified a series of failings but concluded the woman had probably already died before officers were contacted.
Her report found the woman's daughter had phoned the police area control room (ACR) at Govan shortly after 22:00 on Friday 19 February concerned for her mother's safety.
A full description and address were passed on but as a result of a known issue between the Gazetteer mapping system and the command and control systems used by Police Scotland, officers were sent to the wrong house.
They were given the name of the woman in question but no details of her age, physical description or the fact she was a vulnerable person.
As a result, at about 22:35 they roused an 84-year-old woman at the wrong address, failing to notice her name was different from the person they were looking for.
The increasingly worried family of the 52-year-old were told officers had spoken to her and she was safe and well.
However, she was found dead at around 02:40 the following day after officers finally forced entry to the right house more than four-and-a-half hours later.
The PIRC found she was suspected to have died of an accidental overdose of prescribed medication and the time of death was likely to have been before the initial contact with police.
However the report raised concerns about the mapping system and "failings in the actions of both area control room staff and the attending officers".
It recommended that Police Scotland take steps to address the mapping issue, ensure control room staff pass on "all relevant available information" to front-line officers and clarify responsibilities for updating people who report incidents.
Ms Frame said it was "deeply troubling" that the systems issues had not been resolved and "disappointing" the officers had failed to realise the names had not matched up.
She added: "Whilst I recognise from the medical evidence obtained in this particular case that it is likely the 52-year-old woman was dead by the time the alarm was raised, it does not diminish the particular failures identified or the additional distress caused to the woman's family."
In a statement, the woman's family said: "The past 18 months have placed an incredible strain on our family as we have tried to come to terms with the loss of a loving mother and understand the tragic circumstances behind her death.
"We are aware of the PIRC report and are pleased to note that a number of recommendations have been made.
"None of this will bring our mother back but we hope that going forward Police Scotland will look carefully at these recommendations and that valuable lessons have been learned."
Assistant Chief Constable Nelson Telfer said Police Scotland's thoughts were with the family.
"We are sorry for the distress and upset caused by our initial response to the incident," he said.
"We acknowledge and accept the recommendations made by the commissioner in her report and took steps last year to address the issues she has now identified."
He said that since the incident "significant work" had been undertaken to ensure that address information was presented correctly.
"ACR and service centre staff undertake regular training to assist our response to incidents involving risk and vulnerability," he added.
"This is ongoing for all staff.
"We accept we did not get it right in this case and will continue to work to provide excellent front line policing across Scotland."