Changing custom field from List to Multiselection list

[sintaq]

Hi all,
I'm trying to change my custom field's type from List to Multiselection and am getting the Warning message as below, which is expected

"...Changing field type may cause errors and unexpected behaviour if existing values are not consistent with the field's new type. To proceed, click the button below..."

Before I proceed, i just want to gauge the success rate (meaning if i proceed there wont be issue) or if anyone can share their experience doing so. Thanks

[cas]

May I suggest, you install mantis one more time for testing purposes? Then you can check if there any issues.
The succesrate very mucg depends on current and future values.