Overview

UniSim® Design uses a small set of index files to list the species available in the OLI databanks. When these files are out of date or damaged, you may see missing OLI component lists, initialization errors in the OLI_Electrolyte fluid package, or flash errors. In most cases, the fix is simple: delete the OLI index files and let UniSim Design rebuild them.

This article explains what the index files are, when to rebuild them, and how.

Disclaimer: The examples here used UniSim® Design versions R491 through R530 and OLI Engine versions 11.0 and 12.x

What are the OLI index files?

UniSim Design generates the OLI index files from the OLI component (database) interface. They contain the list of OLI species shown in the component list. There are up to three files:

• oliADB.idx
• oliMDB.idx
• oliPDB.idx

Not all of these files may exist on your computer. They are stored in your UniSim Design user folder, and each UniSim Design version has its own folder:

\Documents\UniSim Design R5xx\User

For example, R510 uses \Documents\UniSim Design R510\User and R520 uses \Documents\UniSim Design R520\User.

Note: If your Documents folder is redirected (for example, to OneDrive), the full path will be different. For example:

C:\Users\<username>\OneDrive - <Company>\Documents\UniSim Design R510\User

UniSim Design creates the index files automatically the first time it starts or the first time you use the OLI_Electrolyte fluid package. Deleting them is safe; UniSim Design will recreate them as needed.

When should you rebuild the index files?

Rebuild the OLI index files in any of the following situations:

1. After installing or upgrading the OLI Engine. UniSim Design does not automatically rebuild the species indexes when you install a new version of the OLI Engine. This is a known issue. Always rebuild the index files after linking a new OLI Engine version with the OLI Configuration Tool.
2. The OLI component lists do not appear. The license is valid, the OLI Engine is installed and linked, and you can add the OLI fluid package, but the OLI databanks are missing from the component list. This usually means the index files were not created or are out of date (check the file timestamps).
3. A related symptom: OLI Electrolyte appears under Library Components and the AQ/MSE databank selector shows, but the Components Available in the Library list is empty. This also points to missing or outdated index files.

4. After rebuilding the index files, the OLI species appear in the Components Available in the Library list.
5. After a species is renamed between OLI Engine versions. For example, PIPERAZINE was renamed PIP in OLI Engine 12. Rebuild the index files before substituting the component. See Replacing an OLI Electrolyte component in UniSim® Design.
6. After adding or copying a private OLI databank. If you see errors after copying a databank into your OLI Databanks folder, rebuilding the index files resets the internal species numbering. See Using OLI Databanks in Honeywell UniSim® Design.
7. After a license problem. If UniSim Design was started with an incorrect license (for example, a softkey issued for a different computer), the index files can be corrupted. They remain corrupted even after the correct license is installed, until they are deleted and rebuilt.
8. Unexplained OLI initialization or flash errors. If an OLI case that previously ran now fails, rebuilding the index files is a quick first step before further troubleshooting.

How to rebuild the index files

1. Close UniSim Design.
2. If you have just installed a new OLI Engine, run the OLI Configuration Tool for UniSim Design (as administrator) and confirm that the correct versions are linked. See Configuring the OLI Engine for UniSim® Design.
3. Open the user folder for your version of UniSim Design, for example \Documents\UniSim Design R510\User.
4. Delete the OLI index files: oliADB.idx, oliMDB.idx and oliPDB.idx (whichever are present). Do not delete other .idx files in this folder; they are not related to OLI.
5. Start UniSim Design.
6. Open your case, or create a new component list and select the OLI Electrolyte databank. The index files will be rebuilt automatically.
7. Confirm that OLI Electrolyte appears under Library Components, that the OLI species are listed for the selected databank (AQ or MSE), and that the OLI_Electrolyte fluid package initializes correctly.

Troubleshooting

The index files are not recreated. If the OLI index files do not reappear in the User folder after you start UniSim Design and open an OLI component list, something may be preventing UniSim Design from writing to that folder. Check the following:

• Confirm you are looking in the correct folder for your UniSim Design version, including any OneDrive or network redirection of your Documents folder.
• Confirm you have write permission to the folder.
• Do not copy index files from another computer. They are generated for the local installation, and copying them does not resolve the problem.

If the problem persists, please contact OLI Support and include your UniSim Design version, OLI Engine version, and a copy of the UniSim trace window output.

Related articles

• Configuring the OLI Engine for UniSim® Design
• Understanding the integration of the OLI Engine with UniSim® Design
• Replacing an OLI Electrolyte component in UniSim® Design
• Using OLI Databanks in Honeywell UniSim® Design
• Updating Your Serial Number with OLI Alliance Software