Code doesn't work when 2 workbooks opened

[harveya915]

I have a workbook called Call Info 2.0
On this workbook in Sheet1 I have an image. When I click on the image it brings up a UserForm1
It works all fine and dandy, except for, if I have another workbook opened and when I try to click on the image I get an error:
Run-time error '381': Could not set the List property. Invalid Property array index.
When I hit the debug button, it takes me to the Sheet1 code of the Call Info 2.0:

Sub Image1_Click()
UserForm1.Show vbModeless
End Sub

If I close the second workbook and try clicking the image again, it works! Any help would be appreciated.

 

[MoshiM]

Post your initialization event code

 

[harveya915]

Post your initialization event code

I'm a bit of a noob. All I have learned is from researching. Would you mind explaining a bit more? I can only assume, by what I have kinda learned so far, is that it would look something like this...

Private Sub Workbook_Initialize()
Workbooks("Call Info 2.0.xlsx").Activate
End Sub

And then this would go in the "This Workbook" code?
Am i along the right path?

 

[MoshiM]

What I mean is that I need you to show me the code that generates the error. Do you need the other workbook to be active? In general I'd always recommend declaring references to workbooks/worksheets/ranges for example set WB1= workbooks("Workbook name"). Thisworkbook will always refer to the workbook that the code is found in.