Files corrupt to all run stitches....??

We are having a problem with files that corrupt to all run stitches. We assign colors to customers supplied DST files. Then when they need another edit the emb file we create corrupts to all run stitches. We then have to assign the colors all over again from the DST file. Any idea why this happens on some files randomly?
We use Wilcom software.

Thanks...

Location: 
United States

Never edit a DST or any other Format in Wilcom, unless those files were created in same level and version as your Wilcom.

If your Customer Provided DST file is 100% Good-To-Go with exception of Color asignment, DON'T open the file in your Wilcom software, just load DST file to your machine and manually asign Color / Needle using Control Panel option.

If you use Wilcom Version 2006 (that's any Wilcom version Higher than V9 Wilcom), NEVER Edit ANY Embroidery Format until you RENAME and SAVE original (just in case), then Open, but DO NOT EDIT, then SAVE it as a EMB file in your version. Then Open and edit, rename and SAVE as new EMB, then DST and run a test sew out.

NOTE: If DST file was created in any software program other than exact Wilcom Version / level you're using, always EXPECT the UNEXPECTED, insane issues, such as you experienced.

Know that 9 out of 10 times if the file wasn't created in your software but needs editing (other than color assignment), it's probably faster to redigitize the design from scratch in your version of Wilcom.

Know that you'll need to spend significant amount of Time editing the entire design, all property settings, node placements, etc. to find the Wierd unexpected loss of Design Property settings, and expect multiple Test Sew Outs until you fine-tooth the design, find and fix all the unexpected surprises.