[6.7.2/7.0.0‑beta] Severe startup delay

[Tom G]

Environment
OS: Windows 10 (10.0.26200), x64, admin install mode, RedirectionGuard enforcing
Inno Setup versions compared (same machine, same .iss, byte‑identical source):
• 6.7.1 - FAST (no delay)
• 6.7.2 - SLOW (regression appears here)
• 7.0.0‑beta (32‑bit edition, 32‑bit installer) - SLOW (same regression)
Script: very large single .iss (~33,000 lines; very large [Files] and [Components] sections - thousands of entries; ~10k‑line [Code] section)

Symptom
After InitializeSetup returns, there is a ~50 second freeze with HIGH CPU (single core pegged) BEFORE the wizard appears. No installer/script code runs during the gap (nothing is logged). Not network‑related - network calls in the script complete in milliseconds immediately after the gap.

Reproduction / measurement (from /LOG output, same script)
6.7.1:
  [InitializeSetup] -- OK ...  Extracting temporary file: ...top.bmp  ≈ 4.5 s
6.7.2 and 7.0.0‑beta:
  same gap ≈ 54 s, CPU‑bound, no log lines in between.

top.bmp is the first thing extracted in InitializeWizard, so the delay is entirely inside Inno Setup’s internal preparation between InitializeSetup returning and InitializeWizard being called - before any Pascal script code executes.

Only variable changed: Inno Setup version. Script is byte‑identical. Not caused by script code, network, antivirus, or machine state.

Scope note
The delay scales with the size of the [Files] / [Components] sections. Small scripts likely will NOT reproduce it. A large script is required. A reproducible large script can be provided privately if needed.

Impact
Makes 6.7.2 and 7.0.0‑beta unusable for large installers (users see ~1 minute hang before first page). Forced to stay on 6.7.1 for production.

Ask
• Is there a known change in 6.7.x/7.0 affecting startup / [Files] / [Components] preparation cost that could explain an O(n) worse regression?
• Any directive/workaround to restore 6.7.1 startup behavior on 6.7.2 / 7.0?

Regards,
Tom

[Martijn Laan]

Hi,

Op 19-5-2026 om 15:45 schreef Tom G:

top.bmp is the first thing extracted in InitializeWizard, so the delay is entirely inside Inno Setup’s internal preparation between InitializeSetup returning and InitializeWizard being called - before any Pascal script code executes.

Is top.bmp the first entry in your [Files] section? From the help file:

When solid compression is enabled, be sure to list your temporary files at (or near) the top of the [Files] section. In order to extract an arbitrary file in a solid-compressed installation, Setup must first decompress all prior files (to a temporary buffer in memory). This can result in a substantial delay if a number of other files are listed above the specified file in the [Files] section.

Greetings,
Martijn

[Martijn Laan]

Hi,

For anyone interested: thanks to Tom's help we have found that the slowdown was caused entirely by a very large RTF file, and was entirely unrelated to having a large script.

6.7.2 (and 7.0.0) has a workaround for various bugs in Wine that prevented Setup from recoloring RTF text for any active style.

With such a large RTF (nearly 1 million characters) the workaround is too slow.

I will look into what can be done to support recoloring such a large RTF without a slowdown. This might include only recoloring large RTF files on Windows, at least until Wine has fixed the bugs.

Greetings,
Martijn

Op 19-5-2026 om 15:45 schreef Tom G:

Environment

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[Bill Stewart]

On Tuesday, May 19, 2026 at 12:50:17 PM UTC-6 Martijn Laan wrote:

With such a large RTF (nearly 1 million characters) the workaround is too slow.

How long does it take to page through an RTF file that large in the IS installer window?

I wonder whether this is a case of "don't do that" and rather refer the user to a separate document?

[Martijn Laan]

Op 20-5-2026 om 14:27 schreef 'Bill Stewart' via innosetup:

How long does it take to page through an RTF file that large in the IS installer window?

It's 448 pages when opened with LibreOffice. So... pretty long😁

Nonetheless, in 6.7.3 and 7.0.1 the delay won't be there anymore.

Greetings,
Martijn

[Bill Stewart]

On Wednesday, May 20, 2026 at 7:14:53 AM UTC-6 Martijn Laan wrote:

It's 448 pages when opened with LibreOffice. So... pretty long

I can't imagine anyone scrolling through all of that during an installation process...though I could imagine someone doing "select all" and then pasting it into an editor for later review/printing/etc. It's good there's a fix for that now.