KB: Text String Objects Cannot Be Selected in Schematic Editor

Solution Details

Unexpectedly Inaccessible Text String Objects

Some Text String objects in the Schematic Editor cannot be selected, edited, or otherwise interacted with. Text String objects originating from a schematic template are expected to contain the property ISNOTACCESIBLE=T and are intentionally protected from editing. This article applies only to Text String objects that were not created from a schematic template and have become inaccessible unexpectedly. Examination of the schematic's ASCII file shows that the affected Text String entries contain the property ISNOTACCESIBLE=T. Once this issue appears, subsequent Text String objects in the file may also become inaccessible.

Invalid Accessibility Property Added To File

The issue is caused by corruption within the schematic file. Affected non-template Text String objects incorrectly contain the property ISNOTACCESIBLE=T, which prevents them from being accessible in the editor. Because this property exists only within the schematic file's ASCII representation and is not exposed through standard object property editing, the file must be corrected manually.

Remove Invalid Property From Affected Entries

• Convert the schematic to ASCII format.
• Locate the affected non-template Text String entries.
• Remove the ISNOTACCESIBLE=T property from those entries.
• Reopen the modified schematic and save it back to binary format.
• Verify that all previously inaccessible Text String objects can be selected and edited normally.

Edit ASCII File And Restore Access

1. Save the schematic as ASCII:
   • Select File » Save Copy As….
   • Choose Advanced Schematic ascii (*.SchDoc) and save the file.
2. Open the ASCII file using Notepad or another text editor.
3. Use the Find function to locate the affected Text String (for example, VDD_IO_C).
4. Identify entries similar to:

|RECORD=4|ISNOTACCESIBLE=T|INDEXINSHEET=3|...

5. Confirm that the entry does not belong to a Text String object originating from a schematic template.
6. Remove ISNOTACCESIBLE=T| so the entry becomes:

|RECORD=4|INDEXINSHEET=3|...

7. Save the modified ASCII file and close the editor.
8. Reopen the ASCII file in Altium Designer.
9. Save the file back to binary format using File » Save As and choose Advanced Schematic binary (*.SchDoc).
10. Verify that the previously inaccessible Text String objects can now be selected and edited.

Additional Notes

• Text String objects that originate from a schematic template are expected to be marked as inaccessible and may contain the property ISNOTACCESIBLE=T. This is normal behavior and does not indicate corruption.
• This article applies only to Text String objects that are not template-derived and have become inaccessible unexpectedly.
• Once the issue appears, the corruption can cascade and cause subsequent Text String objects to become inaccessible.
• Create a backup of the ASCII file before making manual modifications.
• After converting the file back to binary format, verify that all previously inaccessible Text String objects can be selected and edited normally.

References

• Working with Text Objects on a Schematic