"I have loaded a design that uses a My Fill pattern, but the fill area is showing a plain pattern."
This will happen if you delete a pattern from your My Fill database and then load a design that uses the pattern. The pattern will use system pattern 3 instead of the deleted My Fill pattern. Either import the deleted pattern picture again, then select it in the My Patterns area of Fill Properties, or choose a different pattern.
"I have a design from a friend and the My Fill pattern for a fill area is different on my computer."
When you have a design from somebody else that contains a fill area with a My Fill pattern, it is likely that their My Fill database will have different patterns to your My Fill database. You must obtain the exported My Fill pattern and import it into your My Fill database, then select the correct pattern in the My Patterns area of Fill Properties.
"When I insert a design outline file (.can) created in a previous version of the software, some fill areas are blank."
If your design contains fill areas using My Fills created in 5D or 4D Design Creator, the My Fills will not initially be present, and therefore cannot be used, in the mySewnet™ Embroidery Software. Use Backup MySettings in 5D or 4D Configure, then restore MySettings in mySewnet™ Configure. Then, in mySewnet™ Digitizing, re-select the My Pattern for the fill area in your design.