Start by telling us what's unique about this tech tree (what you added, changed, etc) so we're not looking for a needle in a haystack.

EDIT: I noticed in a lot of places you changed the Generic Names. Any particular reason for this?

EDIT 2: I found the problem when I tried to download your file. You saved it as a .txt file. It needs to be saved as an .xml

EDIT 3: Turns out the actual solution was different, but equally mundane.

EDIT: Found the solution to my issue, edited original post.

There aren't many unique bits thus far to be fair, just some generic name renames in the food, research and manufacturing trees. Here's the specific techs that I modified directly, aside from the renaming Generic to cluster thing. Added small capitalized dividers telling which line the techs are from to the pastebin (not in the xml file itself): http://pastebin.com/75dBB8ig

I was led to believe through reading other issues in the forums plus looking at the other techtrees that techs and other things can't share InternalNames. In the other techtrees shared techs have InternalName "Race Name""tech name".

It's saved as a .xml on my computer, I just copy and pasted the whole file's code to pastebin, thus when trying to download it it's going to be a txt file.

Would there be anything specific that did that would cause the tree to not generate? I've looked at it and the other base techtrees and don't see how mine would fail to generate while the base ones work fine. Here's the beginning of the tech line and the two techs that require it:

<Tech>
<InternalName>ClusterEngineeringTech</InternalName>
<GenericName>EngineeringTech</GenericName>
<DisplayName>ClusterEngineeringTech_Name</DisplayName>
<TechTree>Cluster_Tree</TechTree>
<ShortDescription>ClusterEngineeringTech_ShortDec</ShortDescription>
<Description>ClusterEngineeringTech_Dec</Description>
<ColorDef>TechOrange</ColorDef>
<Icon>GC3_Engineering_Tech_Icon.png</Icon>
<Bink>GC3_Interstellar_Craft_Temp.bk2</Bink>
<ResearchCost>0</ResearchCost>
<Tags>NonMilitary</Tags>
<AICategoryWeight>
<Military>18</Military>
<Growth>16</Growth>
<Tech>10</Tech>
<Diplomacy>6</Diplomacy>
<Expansion>20</Expansion>
<Wealth>8</Wealth>
<Influence>12</Influence>
<Fortification>14</Fortification>
</AICategoryWeight>
<Prerequ>
<Techs>
<Option>TechTree</Option>
</Techs>
</Prerequ>
</Tech>

<!-- Begin Tech test -->

<Tech>
<InternalName>ClusterInterstellarTravel</InternalName>
<GenericName>InterstellarTravel</GenericName>
<DisplayName>ClusterInterstellarTravel_Name</DisplayName>
<TechTree>Cluster_Tree</TechTree>
<ShortDescription>ClusterInterstellarTravel_ShortDec</ShortDescription>
<Description>ClusterInterstellarTravel_Dec</Description>
<ColorDef>TechBlue</ColorDef>
<Icon>GC3_Intersteller_Craft_Icon.png</Icon>
<Bink>GC3_Interstellar_Craft_Temp.bk2</Bink>
<ResearchCost>42</ResearchCost>
<TechPoints>1</TechPoints>
<AICategoryWeight>
<Military>18</Military>
<Growth>16</Growth>
<Tech>10</Tech>
<Diplomacy>6</Diplomacy>
<Expansion>20</Expansion>
<Wealth>8</Wealth>
<Influence>12</Influence>
<Fortification>14</Fortification>
</AICategoryWeight>
<Prerequ>
<Techs>
<Option>EngineeringTech</Option>
</Techs>
<TechAge>
<Option>AgeOfExpansion</Option>
</TechAge>
</Prerequ>
</Tech>

<Tech>
<InternalName>ClusterOrbitalManufacturing</InternalName>
<GenericName>OrbitalManufacturing</GenericName>
<DisplayName>ClusterOrbitalManufacturing_Name</DisplayName>
<TechTree>Cluster_Tree</TechTree>
<ShortDescription>ClusterOrbitalManufacturing_ShortDec</ShortDescription>
<Description>ClusterOrbitalManufacturing_Dec</Description>
<ColorDef>TechOrange</ColorDef>
<Icon>GC3_Intersteller_Craft_Icon.png</Icon>
<Bink>GC3_Interstellar_Craft_Temp.bk2</Bink>
<ResearchCost>42</ResearchCost>
<TechPoints>1</TechPoints>
<AICategoryWeight>
<Military>18</Military>
<Growth>16</Growth>
<Tech>10</Tech>
<Diplomacy>8</Diplomacy>
<Expansion>20</Expansion>
<Wealth>8</Wealth>
<Influence>14</Influence>
<Fortification>12</Fortification>
</AICategoryWeight>
<Prerequ>
<Techs>
<Option>EngineeringTech</Option>
</Techs>
<TechAge>
<Option>AgeOfExpansion</Option>
</TechAge>
</Prerequ>
</Tech>

<!-- Begin Tech test -->

<Tech>
<InternalName>ClusterOrbitalSpecialization1</InternalName>
<GenericName>OrbitalSpecialization1</GenericName>
<DisplayName>ClusterOrbitalSpecialization1_Name</DisplayName>
<TechTree>Cluster_Tree</TechTree>
<ShortDescription>ClusterOrbitalSpecialization1_ShortDec</ShortDescription>
<Description>ClusterOrbitalSpecialization1_Dec</Description>
<ResearchCost>60</ResearchCost>
<TechPoints>1</TechPoints>
<Specialization>ClusterOrbitalSpecialization</Specialization>
<AICategoryWeight>
<Military>16</Military>
<Growth>14</Growth>
<Tech>8</Tech>
<Diplomacy>6</Diplomacy>
<Expansion>18</Expansion>
<Wealth>6</Wealth>
<Influence>12</Influence>
<Fortification>10</Fortification>
</AICategoryWeight>
<Stats>
<EffectType>Military</EffectType>
<Scope>Global</Scope>
<Target>
<TargetType>Ship</TargetType>
</Target>
<BonusType>Multiplier</BonusType>
<Value>0.1</Value>
</Stats>
<Prerequ>
<Techs>
<Option>OrbitalManufacturing</Option>
</Techs>
<TechAge>
<Option>AgeOfExpansion</Option>
</TechAge>
</Prerequ>
</Tech>

Also to the person who referred to me google, I spent a few hours reading of similar threads on the forums here not being able to find a solution to my issue. I used the forum's own search function and google to try to find problems with techtrees and crashes in general to see if anything would help. Google gives me a bunch of stuff for Galciv2 and the forum's own search function hardly gives me anything. I'll look through the threads again just in case I missed something.