I checked your gallery and found some inconsistencies. You shouldn't need to "copy" your theme across, unless you are upgrading from a BETA version of Imagevue X2. Your custom theme was already saved in a unique location after upgrading and it would not be required to copy it over.
In your "f8cus" theme, there are some deprecated settings. Are you familiar with editing XML? If so, you could try to simply remove the following nodes from your theme:
<thumbshadow>false</thumbshadow>
<thumbnailsarea_alpha>0</thumbnailsarea_alpha>
<horisontalamount>0</horisontalamount>
<verticalamount>0</verticalamount>
<maxamount>0</maxamount>
Else, you may have to redo your theme. Just create a new theme based on "default" and apply settings from your f8cus theme to the new one. What version(date) were you using before upgrading?