unable to perform second level release of pr.kindly help

dear friends,

my client is facing problem related to pr release.he is unable to do second level release of one particular pr.other pr he is able to release.

actually,the pr is having 3 level release,the first level release has been ok,but user in the second level release- is not able to release the pr.

in pr, it is showing small yellow traingle(symbol)

1)i have checked the release strtegy

2)basis consultant checked user profile and access issues related to t-code me54n.we are using standard sap configuration and custimazation only.

3)workflow consultant is telling that -no problem with workflow.

the pe is having account assignment category-"K".

is anything special to be checked.

please provide valuable olution for this issue.

your suggestion are taken valuable.

thanks in advance.

regards,

FLEMMINGS