The company revealed net inflows onto its platform for 2018 were £3.9bn, down from £6.2bn the previous year.
The firm admitted it had suffered from “disruption during the migration of our independent financial adviser platform to a new supplier, which adversely affected our service standards.”
A statement in the results read: “Our teams worked hard to resolve these challenges and advisers are now starting to benefit from the improved functionality and processing capability that the new platform offers.”
It added: “Externally, uncertainty in the political and economic backdrop intensified during the year and this was reflected in a difficult year for investment market performance across most asset classes.
“In our home market, the UK, the prolonged and fraught process of negotiating Britain’s exit from the European Union has weighed down on growth in the economy.
“But Aviva is well placed to deal with this; our locally incorporated and locally regulated businesses in Europe have prepared to minimise the potential operational impact.”
The company also confessed to “challenges of our own making, including our announcement in March 2018 that we were
‘evaluating alternatives’ for the Aviva plc and General Accident plc preference shares.”
It added: “While we responded quickly to certain investor concerns by withdrawing from further action and paid £10m in goodwill and administration costs to compensate those who incurred losses from selling these securities during this period, it was a disappointing episode and lessons have been learned.”
Elsewhere Aviva’s platform assets under administration grew over the year by 12% to £22.6bn.
Aviva previously revealed its chief executive, Mark Wilson, was stepping down to be replaced by Maurice Tulloch.
Mr Tulloch said: “I am excited to be taking over as CEO of Aviva.
“We have strong foundations but we are only scratching the surface of our full potential.
“There’s a huge opportunity here.
“At the heart of it, it’s all about insurance fundamentals, delivering excellent customer experience, tackling complexity and injecting a different pace of change into Aviva.
“And that will be just the start.
“I am determined to re-energise Aviva and deliver long term growth for our shareholders.”
Sir Adrian Montague, chairman, said: “Aviva made steady progress in 2018.
“We grew profits, had a record year for cash remittances and further increased our solvency cover ratio to 204%.
“As a result, the Board has increased the full year dividend by 9% to 30 pence per share.
“Our key profit measure, operating earnings per share, is up 7%.
“Just under half our earnings growth is due to higher profits from our major businesses, with the rest of the increase due to our ordinary share buy-back, debt reduction and a higher net contribution from longevity and assumption changes.
“We increased profit in the UK, where we won more workplace pension schemes and bulk annuity deals, and across our international businesses, where we expanded and diversified our distribution.
“Aviva Investors had a more challenging year due to difficult investment markets and we have continued to invest in our asset management expertise.
“Looking forward, our capital management plan will prioritise debt reduction for the foreseeable future.
“We plan to reduce debt by at least £1.5bn by the end of 2022, saving approximately £90m per year in interest expenses.
“This builds on the £1.4bn of debt repaid over the past two years and will further enhance our financial flexibility.
“The security and sustainability of our dividend remains paramount.
“We are moving to a progressive dividend policy, which will see the dividend maintained or grown over time depending on business performance and growth prospects.”
He added: “We recently announced the appointment of Maurice Tulloch as chief executive.
“Under Maurice’s leadership, we are confident that we can make Aviva a better business for the benefit of our customers and our shareholders.”