Short answer: your configuration does not yet have a line type. This is a gap in your configuration, not a fault. See Set up your configuration, stage by stage for the fix. If your configuration came from a Katapult import, we may need to make this fix for you.
What the message means
Cloneable has nowhere to put the line you want to draw. Every object on the map belongs to a template. The configuration for this job has no template for lines.
The message itself says: "Pick a span or custom line template from the toolbar options first." If a configuration has more than one line type, the map lets you choose. If it has none, there is nothing to choose. You must fix this in the configuration.
Why this happens
Poles and spans are the two required templates in a configuration. A fully set up configuration has a span template. This message appears when one of two things happens.
Someone built the configuration quickly and left the line templates for later.
You need a kind of line that is not a span, such as a guy run or a cable. The original setup did not include it.
Either way, nothing is broken. The setup does not yet describe the thing you want to draw.
The fix
You fix this in the configuration, not on the map. See Set up your configuration, stage by stage. It explains who can change a line template and what to do if you cannot find the controls.
If you draw a span, set the span template for the configuration.
If it is something other than a span, it needs adding as a custom line type.
If your configuration came from a Katapult import, the template pickers on that stage are not shown, so an administrator cannot add a new span or custom line template there directly. Removing an existing one still works. If a Katapult-derived configuration lacks a line template you need, ask us. You cannot fix this yourself.
After you add the template, reopen the job and try again.
What to tell your administrator
Two things help whoever looks into this:
What you wanted to draw. Describe it in your own words, such as a span between two poles, a down guy, or a cable.
Which job you were in, since that identifies the configuration.