Hi, Can any one offer some advice

2 Clutches of Spur thighed eggs laid within a day of each other, incubated in Lucky Reptile Incubator at 33.C with a pot of water.

1 egg hatched on day 63 perfectly

I cracked egg from second batch on day 65, only to find large egg sac, but tortoise doing well Decided to leave the others alone until today day 67 only to find they have all died trapped but still with egg sac's, why am I getting this problem

Hello Maisie,
Firstly it is wrong to crack eggs & open them. The 1st egg can 'pip' days, sometimes weeks before the last.
You say re. the 2nd clutch "have all died trapped, but still with egg sacs." They would'nt have been "trapped" if their yolk sacs were present. They probably had quite a number of days to go. Can you provide more info please about the conditions in the incubator, the hatching medium, etc.
Regards
Tom