Should have given more details.
sqloopenp is in the sqlo or OS component, looks like it was opening something, likely a file.
errno: 0000 001a -> this is typically the errno from a system call, convert 1a to decimal gives us 26.
Thus grep for 26 in errno.h should give us the return code. Unfortunately without the db2 source we have no way of knowing for certain what system call was being executed at probe 20, but given the function name we can assume it was an open()... might be wrong.
If you try again with DIAGLEVEL 4 you may get more details, maybe not.