"No *.stm found for database 'ServerX\Microsoft Information Store\First Storage Group\Mailbox Store (ServerX)'"
"No *.stm found for database 'ServerX\Microsoft Information Store\First Storage Group\Mailbox Store (ServerX)'"
This suggests that the .stm file on server may have been corrupted or found missing. To resolve this error, please perform a Full MS Exchange backup manually via OBM.