Barcelona's net debt increased from €217 Mn (June 2019) to €488 Mn as of June 2020, an increase of €271 Mn. While it's a massive leap, looking at their balance sheet it's understandable. As of June 2019, they had an abysmal current ratio of 0.58

Which is to say that they were liable to pay more during the year than they had money in hand/money coming in. This usually happens if they've lost cash due to unwise investments/speculation/they've used the cash for day to day operations for long term investments.

With Barca, it looks like the latter. The difference between their current liabilities as of June 30, 2019 and the Current assets is €285 Mn. This is the hole that the increased debt (ideally long term) seems to have filled.

Interesting to note that as of June 30 2019 they were even having dues to the tune of €101.9 Mn which would be the personal income tax debited from wages which are to be remitted to the tax authorities each month. As per my rough calculation this turns out to be 7 months dues

That's a serious regulatory issue in most countries. I assume that this is true in Spain. A lack of action by the authorities could also be seen as the Spanish state supporting the club.

They also had dues of €10.5 Mn in VAT & Social Security dues. As on the same date they had dues of €106 Mn to suppliers, €160 Mn to players. This seems to be a consistent theme over the last few years w/ their debt going up from €50 Mn in June 30 2017 to €217 Mn in June 2019

As of June 2019 they also owe €260 Mn to other sporting entities of which €80 Mn was due during next financial year. The increase in debt seems to be to retrospectively plugging the liquidity holes.

It seems highly likely that they will have to continue borrowing to maintain this kind of a burn rate. But in 2019 they declared a profit of €4.5 Mn so that makes them compliant with FFP. This on the whole seems laughable.

They are also looking to raise and eye popping €815 Mn for the stadium upgradation which is to be completed by 2024. That seems like a story on its own.

I'm not an expert on Barca's financials & this is what I could see during a cursory reading of their last year's financial reports and correlating that with the news of their increased debt. But from the outside in looks like a highly mismanaged entity. @RafaelH117