Active separate already exist error on creating work order

Has this started happening all of a sudden? Have you done any database copies or similar and the sequence hasn’t been reset? 

The work order number should be generated by a Oracle Sequence (PCM_COUNTER_WO_SEQ). 

What value to you get if you run 
 

SELECT PCM_COUNTER_WO_SEQ.nextval FROM dual

What version of IFS Applications or IFS Cloud are you working with?

ifs applicaton

we are using index for wo_no which is differnet for different site