If an error occurs during the conversion process, a requester appears displaying one of the following error messages. This list is alphabetical.

Can't open input file
Interchange was unable to open the selected file. The file may have disappeared because another program deleted the file between the time you selected the file in Interchange and the moment of conversion. If you were performing a large number of conversions in the background, it is possible you deleted the file yourself.

Can't open output file
When it tried to write a file, a Converter was unable to open the file. This might occur if you specified a write-protected disk as the destination for the conversion.

Conversion stopped at your request
You pressed the Stop button on the status dialog that appears while Interchange is converting a file.

Error reading file
While importing, the operating system told an Interchange Converter that it was unable to read data from a file. For example, this error occurs if a disk has a "read error."

Error writing file
While creating a new file, a Converter was unable to write some data to disk. This might occur if a floppy disk was removed while the Converter was writing information, or if the disk was full.

Input file corrupted
This error is slightly different than an "Unexpected end of data" error. While reading a file, an Interchange Converter was able to read the data from a file, but something else was wrong with the data. For example, a Converter expected to find three numbers at a certain point in a file, but found two instead.

Invalid disk or directory name
You entered a non-existent disk or directory name. Interchange cannot create new directories for you.

No files are selected to convert
The Selected Files list does not contain any filenames. You clicked the Convert button before you'd selected any files for conversion. Read the "Example Conversion" chapter.

Object too large to convert
This error does not indicate that an object is too "large" in the sense of dimensions or size. It means an object has too many points, edges or polygons.
When writing an object, Converters perform several checks on the number of points, edges, polygons in the object they are being asked to convert. Each 3D format has limits, as described in the "Geometry" section in each Converter's chapter. For example, some formats limit the number of points in an object. If a format is limited to 32,767 points, then you can't store a 40,000 point object in that format. This often happens when converting a hierarchical object to a format that doesn't support hierarchies. The destination Converter will merge the objects into a single object that might contain more points, edges or polygons than allowed in that format. The only solution is to break up the object into smaller pieces, then convert.

Out of memory
During the conversion process, Interchange asks the operating system for pieces of memory. In fact, many thousands of memory allocations may be performed during a conversion. This error occurs if any one request fails. The object might contain too many points, edges or polygons to be converted given the amount of memory in your computer. Or, you might be running another program that has consumed a lot of memory. If possible, shut down these other programs and try again. You can also adjust the amount of virtual memory used by Microsoft Windows.

Unable to create backup file
For some reason, Interchange was not able to carry out your backup choice. If you set the option to make backup files, and if the Converter was unable to rename the older version of the file, it can fail in this way. This can be caused by a write-protected disk.

Unexpected end of data
While reading a file, Interchange unexpectedly encountered the end of the file. Some programs call this an "unexpected end of file" error. For example, if a 3D program crashed while writing out a file, it might have left an incomplete file on disk. Be sure the object can be reloaded into the program that created it.

Unknown conversion request
This error means a Converter has been asked to read or write a format that it does not understand. This error should not occur in the course of normal conversions. It indicates an internal error within Interchange. Please report this to technical support as a bug.

Unknown program error, please notify technical support
This marks an unexpected error. Please report this as a bug.

Unrecognized file type
Before importing a file, Interchange attempts to automatically determine the file's data format. Interchange asks each Converter if the file resembles data that it can import. This error occurs when no Converter can recognize the file.