SBL-DAT-00501 : Invalid search specification ' < ? > '.

We detected an Error which may have occurred for one or more of the following reasons:
Invalid search specification '<?>'. Please continue or ask your systems administrator to check your application configuration if the problem persists.(SBL-DAT-00501)

SBL-DAT-00501

This error can come out of the blue moon and can cause some serious time waste and frustration. I learned to resolve it the hard way. In my case it was only occurring in the dedicated client and same srf was working on server perfectly fine.

This is error doesn't mean there is problem in search spec in eScript or MVLs or BCs. It usually occurs when calculated fields is having issues.

Possible reasons for this error:

1. Any type of syntactical mistake in calculated fields
2. Presence of carriage return in any calculated fields
3. Calculated fields declared as DTYPE_TEXT however they are compared in another calculated field as integer.

How to resolve it?

1. Turn on the siebel logs to level 4 and try the scenario again. And search for the error code in log file. 
2. Just above the error code you should see the calculated expression which is causing issue. 
3. Now go to flat tab and search with this calculation to find calculated field. Once culprit is found, BC recompile after change does the job.

Hope it helps.