The club's failure to pay player bonuses and signing on fees resulted in an embargo at the start of the season but that was lifted when all the cash was paid.
Palace then brought in Claude Davis but failure to pay Ipswich the latest installment for Alan Lee has resulted in the embargo being placed on the club again.
Palace manager Neil Warnock said: "I'm aware of the situation and we will get around it. I'm sure it will be lifted in the next couple of weeks and it's just a case of getting on with it - but I'm still very positive."
Mark Robins warned his Barnsley players the hard work is yet to begin, despite seeing his side record their first win of the season on Tuesday night
The Tykes were 3-2 victors at Derby County to move off the foot of the table, though they still only have four points to their name from the opening seven games.
"We've got to build on this and make sure everybody doesn't get carried away because it's just a first win of the season,” he said.
"I'm pleased for the players because they put a hell of a lot of work in For us it's a start and it gets us up and running a little bit, but with tough games to come.”
The win was not without cost for Barnsley, their midfielder Emil Hallfredsson is expected to be out for two weeks with a knee ligament injury.
Kayode Odejayi has left the Tykes to join Colchester United on a three-month loan.
The move preceded Robins' first signing for the club, signing the free agent Julian Gray on a month-long contact.
The England U21 winger Adam Johnson earned yet more praise after inspiring Middlesbrough to their win over Sheffield Wednesday at Hillsborough.
"Adam is a special talent. There were some moments when he relieved so much pressure by just picking the ball up and beating people,” said Gareth Southgate, the Middlesbrough manager.
"He was outstanding. You win on a team performance and it had to be gritty and resilient, but a couple of moments of class have won us the game."
Boro’s strengthening looks set to continue, with the Hull City forward Caleb Folan due to hold talks over a loan move to the Riverside this week.
It follows the capture of centre-back Sean St Ledger from Preston North End on Tuesday.
Matthew Kilgallon, the Sheffield United defender, looks set to miss Friday’s Steel City derby with a chest infection. Both Sheffield teams go into the match on the back of defeats.