Fixed error with SPFILE parameter in Oracle

Error:
Generate error with alert command to change any parameter which caused error during startup.

SQL> alter system set processes=0 scope=spfile;
System altered.

SQL> shutdown immediate
ORACLE instance shut down.

SQL> startup
Database mounted.
ORA-00020: maximum number of processes () exceeded
Process ID: 23928
Session ID: 26 Serial number: 59446

Solution:
Fixed the SPFILE issue by creating PFILE. You can edit the PFILE for change valid value for the parameter or remove that parameter from the file, so that Oracle automatically pick default value. You can get old value from alert log file.

Create the PFILE from SPFILE.

SQLPLUS / as sysdba
create pfile='D:\initfixed.ora' from spfile;
File created.

Edit the PFILE in notepad .
If you know the exact value then replace it (get from alert log file) otherwise remove the parameter from PFILE and save it.

-- In example, Removed following entry from pfile and save it.
*.processes=0

Create SPFILE from PFILE.

SQL> create spfile from pfile='D:\initfixed.ora';
File created.

Start the database.

SQL> startup
ORACLE instance started.
Total System Global Area 1610609464 bytes
Fixed Size                  9028408 bytes
Variable Size            1258291200 bytes
Database Buffers          335544320 bytes
Redo Buffers                7745536 bytes
Database mounted.
Database opened.