Cannot use "?" in Explain Plan

Please share the SQL logs (Help | Show SQL Logs in Finder) after reproducing the issue.
There should be something like 

sql> SELECT 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 FROM dual 
[2015-10-01 23:11:07] 1 row retrieved starting from 1 in 583ms (execution: 515ms, fetching: 68ms) 
[2015-10-01 23:11:13] completed in 122ms 
sql> EXPLAIN PLAN SET statement_id='oxe/U0rhXwQ58Swo+0VA7Q==' FOR SELECT 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 FROM dual; SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE','oxe/U0rhXwQ58Swo+0VA7Q==')) 
[2015-10-01 23:11:18] [22019][911] ORA-00911: invalid character

HR> EXPLAIN PLAN SET STATEMENT_ID = 'oj0tgh/14pN9ZXg4J/hA6Q==' INTO "PLAN_TABLE" FOR select * from DUAL where dummy = ?
[2022-11-09 11:42:20] [22019][911] ORA-00911: invalid character
[2022-11-09 11:42:20] Position: 114

Thank you for being so patient.

After performing some tests, we are confirming that this is a bug. As a workaround, please substitute the question sign (?) with (:1), and it should give you the desired result. See screenshot



As soon as our developer will create a bug report on youtrack, we'll provide you with a link to follow this issue.

Sadly, using ":1" instead of "?" does not work properly. It seems that when using ":1" the order of the values in the WHERE clause is not preserved, thus leading to wrong cost in explain plan. Using "?" works for a co-worker of mine, and we replicate the results there.

FYI, we have found out that EXPLAIN PLAN works properly using "?" in IntelliJ 2021.2 Build #IU-212.4746.92, but this is as far as we can see the last version where it works. It does not work in IntelliJ 2021.2.4 Build #IU-212.5712.43 or any later build we've tried. Will you be able to fix this?