The most common cause of this situation is an accumulation of "exported-change-not-reimported" errors.
You can increase the error limit to a sufficient value so that synchronization can finish processing all objects before the error limit is reached. Given the opportunity to finish, the synchronization process will eventually resolve the temporary error conditions. The error limit is configured by adding the ErrorLimit (REG_DWORD) entry to the following registry subkey:
If you are using MIIS / ILM / IIFP
If you are using FIM 2010
The value is an integer in the range of 0-100000.
• Value set to 0 = Error limit set to 100000
• Value in the range of 1-99999 = Error limit set to value
• Value set to 100000 = Error limit set to 100000
• Value set greater than 100000 = Error limit set to 100000
• No key present = Default error limit set to 5000
Note The miiserver service must be restarted after modifying this registry key.