I have had this issue for a while now with no help from Cool-er. I was given my reader in the middle of October by my husband, downloaded a few books which worked fine but the reader kept switching itself off & back on every few pages. I read up on the website and updated the firmware. Since then I have had issues with the device. I get the same error message as you each time I try to open one of the e-pub books that I could previously open. They work in ADE on the PC.
I contacted Cooler by e-mail on 23rd October about the problem and heard nothing. On 6th November I rang their UK phone number (which is answered by a recorded message only) and e-mailed them again saying that I was less than satisfied by being ignored! This was their reply :
"I apologise for the delayed response. We are in the process of finding a solution to the problem you are experiencing. This issue has been brought to our attention by several other customers and our technical support team is working diligently towards a solution. We have contacted adobe numerous times and have had no luck in getting a response. We sincerely apologise for this inconvenience. This is not how we want our customers to experience the COOL-ER"
In other words, they are blaming Adobe. Needless to say I have still heard nothing - I'd be interested to know if anybody has heard any more about a fix yet.
The solution is to deactivate the device in ADE then do a factory reset,
1. press and hold menu button until the LED light blinks (left bottom
2. press and hold the volume + button until the LED light blinks (right top
3. press and hold the volume - button until the LED light blinks (right
Display will confirm factory reset and then reboot, all you now need to do
is open ADE and reactivate and all should work.
Thank you - that works! Still had no fix from Cooler themselves - I'm surprised they didn't suggest this to be honest, so customer service wise I still think they're shocking but am very pleased to have got it working properly!